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1 /*
2  * btree.c - NILFS B-tree.
3  *
4  * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2 of the License, or
9  * (at your option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
19  *
20  * Written by Koji Sato <koji@osrg.net>.
21  */
22 
23 #include <linux/slab.h>
24 #include <linux/string.h>
25 #include <linux/errno.h>
26 #include <linux/pagevec.h>
27 #include "nilfs.h"
28 #include "page.h"
29 #include "btnode.h"
30 #include "btree.h"
31 #include "alloc.h"
32 #include "dat.h"
33 
34 static void __nilfs_btree_init(struct nilfs_bmap *bmap);
35 
nilfs_btree_alloc_path(void)36 static struct nilfs_btree_path *nilfs_btree_alloc_path(void)
37 {
38 	struct nilfs_btree_path *path;
39 	int level = NILFS_BTREE_LEVEL_DATA;
40 
41 	path = kmem_cache_alloc(nilfs_btree_path_cache, GFP_NOFS);
42 	if (path == NULL)
43 		goto out;
44 
45 	for (; level < NILFS_BTREE_LEVEL_MAX; level++) {
46 		path[level].bp_bh = NULL;
47 		path[level].bp_sib_bh = NULL;
48 		path[level].bp_index = 0;
49 		path[level].bp_oldreq.bpr_ptr = NILFS_BMAP_INVALID_PTR;
50 		path[level].bp_newreq.bpr_ptr = NILFS_BMAP_INVALID_PTR;
51 		path[level].bp_op = NULL;
52 	}
53 
54 out:
55 	return path;
56 }
57 
nilfs_btree_free_path(struct nilfs_btree_path * path)58 static void nilfs_btree_free_path(struct nilfs_btree_path *path)
59 {
60 	int level = NILFS_BTREE_LEVEL_DATA;
61 
62 	for (; level < NILFS_BTREE_LEVEL_MAX; level++)
63 		brelse(path[level].bp_bh);
64 
65 	kmem_cache_free(nilfs_btree_path_cache, path);
66 }
67 
68 /*
69  * B-tree node operations
70  */
nilfs_btree_get_new_block(const struct nilfs_bmap * btree,__u64 ptr,struct buffer_head ** bhp)71 static int nilfs_btree_get_new_block(const struct nilfs_bmap *btree,
72 				     __u64 ptr, struct buffer_head **bhp)
73 {
74 	struct address_space *btnc = &NILFS_BMAP_I(btree)->i_btnode_cache;
75 	struct buffer_head *bh;
76 
77 	bh = nilfs_btnode_create_block(btnc, ptr);
78 	if (!bh)
79 		return -ENOMEM;
80 
81 	set_buffer_nilfs_volatile(bh);
82 	*bhp = bh;
83 	return 0;
84 }
85 
nilfs_btree_node_get_flags(const struct nilfs_btree_node * node)86 static int nilfs_btree_node_get_flags(const struct nilfs_btree_node *node)
87 {
88 	return node->bn_flags;
89 }
90 
91 static void
nilfs_btree_node_set_flags(struct nilfs_btree_node * node,int flags)92 nilfs_btree_node_set_flags(struct nilfs_btree_node *node, int flags)
93 {
94 	node->bn_flags = flags;
95 }
96 
nilfs_btree_node_root(const struct nilfs_btree_node * node)97 static int nilfs_btree_node_root(const struct nilfs_btree_node *node)
98 {
99 	return nilfs_btree_node_get_flags(node) & NILFS_BTREE_NODE_ROOT;
100 }
101 
nilfs_btree_node_get_level(const struct nilfs_btree_node * node)102 static int nilfs_btree_node_get_level(const struct nilfs_btree_node *node)
103 {
104 	return node->bn_level;
105 }
106 
107 static void
nilfs_btree_node_set_level(struct nilfs_btree_node * node,int level)108 nilfs_btree_node_set_level(struct nilfs_btree_node *node, int level)
109 {
110 	node->bn_level = level;
111 }
112 
nilfs_btree_node_get_nchildren(const struct nilfs_btree_node * node)113 static int nilfs_btree_node_get_nchildren(const struct nilfs_btree_node *node)
114 {
115 	return le16_to_cpu(node->bn_nchildren);
116 }
117 
118 static void
nilfs_btree_node_set_nchildren(struct nilfs_btree_node * node,int nchildren)119 nilfs_btree_node_set_nchildren(struct nilfs_btree_node *node, int nchildren)
120 {
121 	node->bn_nchildren = cpu_to_le16(nchildren);
122 }
123 
nilfs_btree_node_size(const struct nilfs_bmap * btree)124 static int nilfs_btree_node_size(const struct nilfs_bmap *btree)
125 {
126 	return 1 << btree->b_inode->i_blkbits;
127 }
128 
nilfs_btree_nchildren_per_block(const struct nilfs_bmap * btree)129 static int nilfs_btree_nchildren_per_block(const struct nilfs_bmap *btree)
130 {
131 	return btree->b_nchildren_per_block;
132 }
133 
134 static __le64 *
nilfs_btree_node_dkeys(const struct nilfs_btree_node * node)135 nilfs_btree_node_dkeys(const struct nilfs_btree_node *node)
136 {
137 	return (__le64 *)((char *)(node + 1) +
138 			  (nilfs_btree_node_root(node) ?
139 			   0 : NILFS_BTREE_NODE_EXTRA_PAD_SIZE));
140 }
141 
142 static __le64 *
nilfs_btree_node_dptrs(const struct nilfs_btree_node * node,int ncmax)143 nilfs_btree_node_dptrs(const struct nilfs_btree_node *node, int ncmax)
144 {
145 	return (__le64 *)(nilfs_btree_node_dkeys(node) + ncmax);
146 }
147 
148 static __u64
nilfs_btree_node_get_key(const struct nilfs_btree_node * node,int index)149 nilfs_btree_node_get_key(const struct nilfs_btree_node *node, int index)
150 {
151 	return le64_to_cpu(*(nilfs_btree_node_dkeys(node) + index));
152 }
153 
154 static void
nilfs_btree_node_set_key(struct nilfs_btree_node * node,int index,__u64 key)155 nilfs_btree_node_set_key(struct nilfs_btree_node *node, int index, __u64 key)
156 {
157 	*(nilfs_btree_node_dkeys(node) + index) = cpu_to_le64(key);
158 }
159 
160 static __u64
nilfs_btree_node_get_ptr(const struct nilfs_btree_node * node,int index,int ncmax)161 nilfs_btree_node_get_ptr(const struct nilfs_btree_node *node, int index,
162 			 int ncmax)
163 {
164 	return le64_to_cpu(*(nilfs_btree_node_dptrs(node, ncmax) + index));
165 }
166 
167 static void
nilfs_btree_node_set_ptr(struct nilfs_btree_node * node,int index,__u64 ptr,int ncmax)168 nilfs_btree_node_set_ptr(struct nilfs_btree_node *node, int index, __u64 ptr,
169 			 int ncmax)
170 {
171 	*(nilfs_btree_node_dptrs(node, ncmax) + index) = cpu_to_le64(ptr);
172 }
173 
nilfs_btree_node_init(struct nilfs_btree_node * node,int flags,int level,int nchildren,int ncmax,const __u64 * keys,const __u64 * ptrs)174 static void nilfs_btree_node_init(struct nilfs_btree_node *node, int flags,
175 				  int level, int nchildren, int ncmax,
176 				  const __u64 *keys, const __u64 *ptrs)
177 {
178 	__le64 *dkeys;
179 	__le64 *dptrs;
180 	int i;
181 
182 	nilfs_btree_node_set_flags(node, flags);
183 	nilfs_btree_node_set_level(node, level);
184 	nilfs_btree_node_set_nchildren(node, nchildren);
185 
186 	dkeys = nilfs_btree_node_dkeys(node);
187 	dptrs = nilfs_btree_node_dptrs(node, ncmax);
188 	for (i = 0; i < nchildren; i++) {
189 		dkeys[i] = cpu_to_le64(keys[i]);
190 		dptrs[i] = cpu_to_le64(ptrs[i]);
191 	}
192 }
193 
194 /* Assume the buffer heads corresponding to left and right are locked. */
nilfs_btree_node_move_left(struct nilfs_btree_node * left,struct nilfs_btree_node * right,int n,int lncmax,int rncmax)195 static void nilfs_btree_node_move_left(struct nilfs_btree_node *left,
196 				       struct nilfs_btree_node *right,
197 				       int n, int lncmax, int rncmax)
198 {
199 	__le64 *ldkeys, *rdkeys;
200 	__le64 *ldptrs, *rdptrs;
201 	int lnchildren, rnchildren;
202 
203 	ldkeys = nilfs_btree_node_dkeys(left);
204 	ldptrs = nilfs_btree_node_dptrs(left, lncmax);
205 	lnchildren = nilfs_btree_node_get_nchildren(left);
206 
207 	rdkeys = nilfs_btree_node_dkeys(right);
208 	rdptrs = nilfs_btree_node_dptrs(right, rncmax);
209 	rnchildren = nilfs_btree_node_get_nchildren(right);
210 
211 	memcpy(ldkeys + lnchildren, rdkeys, n * sizeof(*rdkeys));
212 	memcpy(ldptrs + lnchildren, rdptrs, n * sizeof(*rdptrs));
213 	memmove(rdkeys, rdkeys + n, (rnchildren - n) * sizeof(*rdkeys));
214 	memmove(rdptrs, rdptrs + n, (rnchildren - n) * sizeof(*rdptrs));
215 
216 	lnchildren += n;
217 	rnchildren -= n;
218 	nilfs_btree_node_set_nchildren(left, lnchildren);
219 	nilfs_btree_node_set_nchildren(right, rnchildren);
220 }
221 
222 /* Assume that the buffer heads corresponding to left and right are locked. */
nilfs_btree_node_move_right(struct nilfs_btree_node * left,struct nilfs_btree_node * right,int n,int lncmax,int rncmax)223 static void nilfs_btree_node_move_right(struct nilfs_btree_node *left,
224 					struct nilfs_btree_node *right,
225 					int n, int lncmax, int rncmax)
226 {
227 	__le64 *ldkeys, *rdkeys;
228 	__le64 *ldptrs, *rdptrs;
229 	int lnchildren, rnchildren;
230 
231 	ldkeys = nilfs_btree_node_dkeys(left);
232 	ldptrs = nilfs_btree_node_dptrs(left, lncmax);
233 	lnchildren = nilfs_btree_node_get_nchildren(left);
234 
235 	rdkeys = nilfs_btree_node_dkeys(right);
236 	rdptrs = nilfs_btree_node_dptrs(right, rncmax);
237 	rnchildren = nilfs_btree_node_get_nchildren(right);
238 
239 	memmove(rdkeys + n, rdkeys, rnchildren * sizeof(*rdkeys));
240 	memmove(rdptrs + n, rdptrs, rnchildren * sizeof(*rdptrs));
241 	memcpy(rdkeys, ldkeys + lnchildren - n, n * sizeof(*rdkeys));
242 	memcpy(rdptrs, ldptrs + lnchildren - n, n * sizeof(*rdptrs));
243 
244 	lnchildren -= n;
245 	rnchildren += n;
246 	nilfs_btree_node_set_nchildren(left, lnchildren);
247 	nilfs_btree_node_set_nchildren(right, rnchildren);
248 }
249 
250 /* Assume that the buffer head corresponding to node is locked. */
nilfs_btree_node_insert(struct nilfs_btree_node * node,int index,__u64 key,__u64 ptr,int ncmax)251 static void nilfs_btree_node_insert(struct nilfs_btree_node *node, int index,
252 				    __u64 key, __u64 ptr, int ncmax)
253 {
254 	__le64 *dkeys;
255 	__le64 *dptrs;
256 	int nchildren;
257 
258 	dkeys = nilfs_btree_node_dkeys(node);
259 	dptrs = nilfs_btree_node_dptrs(node, ncmax);
260 	nchildren = nilfs_btree_node_get_nchildren(node);
261 	if (index < nchildren) {
262 		memmove(dkeys + index + 1, dkeys + index,
263 			(nchildren - index) * sizeof(*dkeys));
264 		memmove(dptrs + index + 1, dptrs + index,
265 			(nchildren - index) * sizeof(*dptrs));
266 	}
267 	dkeys[index] = cpu_to_le64(key);
268 	dptrs[index] = cpu_to_le64(ptr);
269 	nchildren++;
270 	nilfs_btree_node_set_nchildren(node, nchildren);
271 }
272 
273 /* Assume that the buffer head corresponding to node is locked. */
nilfs_btree_node_delete(struct nilfs_btree_node * node,int index,__u64 * keyp,__u64 * ptrp,int ncmax)274 static void nilfs_btree_node_delete(struct nilfs_btree_node *node, int index,
275 				    __u64 *keyp, __u64 *ptrp, int ncmax)
276 {
277 	__u64 key;
278 	__u64 ptr;
279 	__le64 *dkeys;
280 	__le64 *dptrs;
281 	int nchildren;
282 
283 	dkeys = nilfs_btree_node_dkeys(node);
284 	dptrs = nilfs_btree_node_dptrs(node, ncmax);
285 	key = le64_to_cpu(dkeys[index]);
286 	ptr = le64_to_cpu(dptrs[index]);
287 	nchildren = nilfs_btree_node_get_nchildren(node);
288 	if (keyp != NULL)
289 		*keyp = key;
290 	if (ptrp != NULL)
291 		*ptrp = ptr;
292 
293 	if (index < nchildren - 1) {
294 		memmove(dkeys + index, dkeys + index + 1,
295 			(nchildren - index - 1) * sizeof(*dkeys));
296 		memmove(dptrs + index, dptrs + index + 1,
297 			(nchildren - index - 1) * sizeof(*dptrs));
298 	}
299 	nchildren--;
300 	nilfs_btree_node_set_nchildren(node, nchildren);
301 }
302 
nilfs_btree_node_lookup(const struct nilfs_btree_node * node,__u64 key,int * indexp)303 static int nilfs_btree_node_lookup(const struct nilfs_btree_node *node,
304 				   __u64 key, int *indexp)
305 {
306 	__u64 nkey;
307 	int index, low, high, s;
308 
309 	/* binary search */
310 	low = 0;
311 	high = nilfs_btree_node_get_nchildren(node) - 1;
312 	index = 0;
313 	s = 0;
314 	while (low <= high) {
315 		index = (low + high) / 2;
316 		nkey = nilfs_btree_node_get_key(node, index);
317 		if (nkey == key) {
318 			s = 0;
319 			goto out;
320 		} else if (nkey < key) {
321 			low = index + 1;
322 			s = -1;
323 		} else {
324 			high = index - 1;
325 			s = 1;
326 		}
327 	}
328 
329 	/* adjust index */
330 	if (nilfs_btree_node_get_level(node) > NILFS_BTREE_LEVEL_NODE_MIN) {
331 		if (s > 0 && index > 0)
332 			index--;
333 	} else if (s < 0)
334 		index++;
335 
336  out:
337 	*indexp = index;
338 
339 	return s == 0;
340 }
341 
342 /**
343  * nilfs_btree_node_broken - verify consistency of btree node
344  * @node: btree node block to be examined
345  * @size: node size (in bytes)
346  * @blocknr: block number
347  *
348  * Return Value: If node is broken, 1 is returned. Otherwise, 0 is returned.
349  */
nilfs_btree_node_broken(const struct nilfs_btree_node * node,size_t size,sector_t blocknr)350 static int nilfs_btree_node_broken(const struct nilfs_btree_node *node,
351 				   size_t size, sector_t blocknr)
352 {
353 	int level, flags, nchildren;
354 	int ret = 0;
355 
356 	level = nilfs_btree_node_get_level(node);
357 	flags = nilfs_btree_node_get_flags(node);
358 	nchildren = nilfs_btree_node_get_nchildren(node);
359 
360 	if (unlikely(level < NILFS_BTREE_LEVEL_NODE_MIN ||
361 		     level >= NILFS_BTREE_LEVEL_MAX ||
362 		     (flags & NILFS_BTREE_NODE_ROOT) ||
363 		     nchildren < 0 ||
364 		     nchildren > NILFS_BTREE_NODE_NCHILDREN_MAX(size))) {
365 		printk(KERN_CRIT "NILFS: bad btree node (blocknr=%llu): "
366 		       "level = %d, flags = 0x%x, nchildren = %d\n",
367 		       (unsigned long long)blocknr, level, flags, nchildren);
368 		ret = 1;
369 	}
370 	return ret;
371 }
372 
373 /**
374  * nilfs_btree_root_broken - verify consistency of btree root node
375  * @node: btree root node to be examined
376  * @ino: inode number
377  *
378  * Return Value: If node is broken, 1 is returned. Otherwise, 0 is returned.
379  */
nilfs_btree_root_broken(const struct nilfs_btree_node * node,unsigned long ino)380 static int nilfs_btree_root_broken(const struct nilfs_btree_node *node,
381 				   unsigned long ino)
382 {
383 	int level, flags, nchildren;
384 	int ret = 0;
385 
386 	level = nilfs_btree_node_get_level(node);
387 	flags = nilfs_btree_node_get_flags(node);
388 	nchildren = nilfs_btree_node_get_nchildren(node);
389 
390 	if (unlikely(level < NILFS_BTREE_LEVEL_NODE_MIN ||
391 		     level >= NILFS_BTREE_LEVEL_MAX ||
392 		     nchildren < 0 ||
393 		     nchildren > NILFS_BTREE_ROOT_NCHILDREN_MAX)) {
394 		pr_crit("NILFS: bad btree root (inode number=%lu): level = %d, flags = 0x%x, nchildren = %d\n",
395 			ino, level, flags, nchildren);
396 		ret = 1;
397 	}
398 	return ret;
399 }
400 
nilfs_btree_broken_node_block(struct buffer_head * bh)401 int nilfs_btree_broken_node_block(struct buffer_head *bh)
402 {
403 	int ret;
404 
405 	if (buffer_nilfs_checked(bh))
406 		return 0;
407 
408 	ret = nilfs_btree_node_broken((struct nilfs_btree_node *)bh->b_data,
409 				       bh->b_size, bh->b_blocknr);
410 	if (likely(!ret))
411 		set_buffer_nilfs_checked(bh);
412 	return ret;
413 }
414 
415 static struct nilfs_btree_node *
nilfs_btree_get_root(const struct nilfs_bmap * btree)416 nilfs_btree_get_root(const struct nilfs_bmap *btree)
417 {
418 	return (struct nilfs_btree_node *)btree->b_u.u_data;
419 }
420 
421 static struct nilfs_btree_node *
nilfs_btree_get_nonroot_node(const struct nilfs_btree_path * path,int level)422 nilfs_btree_get_nonroot_node(const struct nilfs_btree_path *path, int level)
423 {
424 	return (struct nilfs_btree_node *)path[level].bp_bh->b_data;
425 }
426 
427 static struct nilfs_btree_node *
nilfs_btree_get_sib_node(const struct nilfs_btree_path * path,int level)428 nilfs_btree_get_sib_node(const struct nilfs_btree_path *path, int level)
429 {
430 	return (struct nilfs_btree_node *)path[level].bp_sib_bh->b_data;
431 }
432 
nilfs_btree_height(const struct nilfs_bmap * btree)433 static int nilfs_btree_height(const struct nilfs_bmap *btree)
434 {
435 	return nilfs_btree_node_get_level(nilfs_btree_get_root(btree)) + 1;
436 }
437 
438 static struct nilfs_btree_node *
nilfs_btree_get_node(const struct nilfs_bmap * btree,const struct nilfs_btree_path * path,int level,int * ncmaxp)439 nilfs_btree_get_node(const struct nilfs_bmap *btree,
440 		     const struct nilfs_btree_path *path,
441 		     int level, int *ncmaxp)
442 {
443 	struct nilfs_btree_node *node;
444 
445 	if (level == nilfs_btree_height(btree) - 1) {
446 		node = nilfs_btree_get_root(btree);
447 		*ncmaxp = NILFS_BTREE_ROOT_NCHILDREN_MAX;
448 	} else {
449 		node = nilfs_btree_get_nonroot_node(path, level);
450 		*ncmaxp = nilfs_btree_nchildren_per_block(btree);
451 	}
452 	return node;
453 }
454 
455 static int
nilfs_btree_bad_node(struct nilfs_btree_node * node,int level)456 nilfs_btree_bad_node(struct nilfs_btree_node *node, int level)
457 {
458 	if (unlikely(nilfs_btree_node_get_level(node) != level)) {
459 		dump_stack();
460 		printk(KERN_CRIT "NILFS: btree level mismatch: %d != %d\n",
461 		       nilfs_btree_node_get_level(node), level);
462 		return 1;
463 	}
464 	return 0;
465 }
466 
467 struct nilfs_btree_readahead_info {
468 	struct nilfs_btree_node *node;	/* parent node */
469 	int max_ra_blocks;		/* max nof blocks to read ahead */
470 	int index;			/* current index on the parent node */
471 	int ncmax;			/* nof children in the parent node */
472 };
473 
__nilfs_btree_get_block(const struct nilfs_bmap * btree,__u64 ptr,struct buffer_head ** bhp,const struct nilfs_btree_readahead_info * ra)474 static int __nilfs_btree_get_block(const struct nilfs_bmap *btree, __u64 ptr,
475 				   struct buffer_head **bhp,
476 				   const struct nilfs_btree_readahead_info *ra)
477 {
478 	struct address_space *btnc = &NILFS_BMAP_I(btree)->i_btnode_cache;
479 	struct buffer_head *bh, *ra_bh;
480 	sector_t submit_ptr = 0;
481 	int ret;
482 
483 	ret = nilfs_btnode_submit_block(btnc, ptr, 0, READ, &bh, &submit_ptr);
484 	if (ret) {
485 		if (ret != -EEXIST)
486 			return ret;
487 		goto out_check;
488 	}
489 
490 	if (ra) {
491 		int i, n;
492 		__u64 ptr2;
493 
494 		/* read ahead sibling nodes */
495 		for (n = ra->max_ra_blocks, i = ra->index + 1;
496 		     n > 0 && i < ra->ncmax; n--, i++) {
497 			ptr2 = nilfs_btree_node_get_ptr(ra->node, i, ra->ncmax);
498 
499 			ret = nilfs_btnode_submit_block(btnc, ptr2, 0, READA,
500 							&ra_bh, &submit_ptr);
501 			if (likely(!ret || ret == -EEXIST))
502 				brelse(ra_bh);
503 			else if (ret != -EBUSY)
504 				break;
505 			if (!buffer_locked(bh))
506 				goto out_no_wait;
507 		}
508 	}
509 
510 	wait_on_buffer(bh);
511 
512  out_no_wait:
513 	if (!buffer_uptodate(bh)) {
514 		brelse(bh);
515 		return -EIO;
516 	}
517 
518  out_check:
519 	if (nilfs_btree_broken_node_block(bh)) {
520 		clear_buffer_uptodate(bh);
521 		brelse(bh);
522 		return -EINVAL;
523 	}
524 
525 	*bhp = bh;
526 	return 0;
527 }
528 
nilfs_btree_get_block(const struct nilfs_bmap * btree,__u64 ptr,struct buffer_head ** bhp)529 static int nilfs_btree_get_block(const struct nilfs_bmap *btree, __u64 ptr,
530 				   struct buffer_head **bhp)
531 {
532 	return __nilfs_btree_get_block(btree, ptr, bhp, NULL);
533 }
534 
nilfs_btree_do_lookup(const struct nilfs_bmap * btree,struct nilfs_btree_path * path,__u64 key,__u64 * ptrp,int minlevel,int readahead)535 static int nilfs_btree_do_lookup(const struct nilfs_bmap *btree,
536 				 struct nilfs_btree_path *path,
537 				 __u64 key, __u64 *ptrp, int minlevel,
538 				 int readahead)
539 {
540 	struct nilfs_btree_node *node;
541 	struct nilfs_btree_readahead_info p, *ra;
542 	__u64 ptr;
543 	int level, index, found, ncmax, ret;
544 
545 	node = nilfs_btree_get_root(btree);
546 	level = nilfs_btree_node_get_level(node);
547 	if (level < minlevel || nilfs_btree_node_get_nchildren(node) <= 0)
548 		return -ENOENT;
549 
550 	found = nilfs_btree_node_lookup(node, key, &index);
551 	ptr = nilfs_btree_node_get_ptr(node, index,
552 				       NILFS_BTREE_ROOT_NCHILDREN_MAX);
553 	path[level].bp_bh = NULL;
554 	path[level].bp_index = index;
555 
556 	ncmax = nilfs_btree_nchildren_per_block(btree);
557 
558 	while (--level >= minlevel) {
559 		ra = NULL;
560 		if (level == NILFS_BTREE_LEVEL_NODE_MIN && readahead) {
561 			p.node = nilfs_btree_get_node(btree, path, level + 1,
562 						      &p.ncmax);
563 			p.index = index;
564 			p.max_ra_blocks = 7;
565 			ra = &p;
566 		}
567 		ret = __nilfs_btree_get_block(btree, ptr, &path[level].bp_bh,
568 					      ra);
569 		if (ret < 0)
570 			return ret;
571 
572 		node = nilfs_btree_get_nonroot_node(path, level);
573 		if (nilfs_btree_bad_node(node, level))
574 			return -EINVAL;
575 		if (!found)
576 			found = nilfs_btree_node_lookup(node, key, &index);
577 		else
578 			index = 0;
579 		if (index < ncmax) {
580 			ptr = nilfs_btree_node_get_ptr(node, index, ncmax);
581 		} else {
582 			WARN_ON(found || level != NILFS_BTREE_LEVEL_NODE_MIN);
583 			/* insert */
584 			ptr = NILFS_BMAP_INVALID_PTR;
585 		}
586 		path[level].bp_index = index;
587 	}
588 	if (!found)
589 		return -ENOENT;
590 
591 	if (ptrp != NULL)
592 		*ptrp = ptr;
593 
594 	return 0;
595 }
596 
nilfs_btree_do_lookup_last(const struct nilfs_bmap * btree,struct nilfs_btree_path * path,__u64 * keyp,__u64 * ptrp)597 static int nilfs_btree_do_lookup_last(const struct nilfs_bmap *btree,
598 				      struct nilfs_btree_path *path,
599 				      __u64 *keyp, __u64 *ptrp)
600 {
601 	struct nilfs_btree_node *node;
602 	__u64 ptr;
603 	int index, level, ncmax, ret;
604 
605 	node = nilfs_btree_get_root(btree);
606 	index = nilfs_btree_node_get_nchildren(node) - 1;
607 	if (index < 0)
608 		return -ENOENT;
609 	level = nilfs_btree_node_get_level(node);
610 	ptr = nilfs_btree_node_get_ptr(node, index,
611 				       NILFS_BTREE_ROOT_NCHILDREN_MAX);
612 	path[level].bp_bh = NULL;
613 	path[level].bp_index = index;
614 	ncmax = nilfs_btree_nchildren_per_block(btree);
615 
616 	for (level--; level > 0; level--) {
617 		ret = nilfs_btree_get_block(btree, ptr, &path[level].bp_bh);
618 		if (ret < 0)
619 			return ret;
620 		node = nilfs_btree_get_nonroot_node(path, level);
621 		if (nilfs_btree_bad_node(node, level))
622 			return -EINVAL;
623 		index = nilfs_btree_node_get_nchildren(node) - 1;
624 		ptr = nilfs_btree_node_get_ptr(node, index, ncmax);
625 		path[level].bp_index = index;
626 	}
627 
628 	if (keyp != NULL)
629 		*keyp = nilfs_btree_node_get_key(node, index);
630 	if (ptrp != NULL)
631 		*ptrp = ptr;
632 
633 	return 0;
634 }
635 
nilfs_btree_lookup(const struct nilfs_bmap * btree,__u64 key,int level,__u64 * ptrp)636 static int nilfs_btree_lookup(const struct nilfs_bmap *btree,
637 			      __u64 key, int level, __u64 *ptrp)
638 {
639 	struct nilfs_btree_path *path;
640 	int ret;
641 
642 	path = nilfs_btree_alloc_path();
643 	if (path == NULL)
644 		return -ENOMEM;
645 
646 	ret = nilfs_btree_do_lookup(btree, path, key, ptrp, level, 0);
647 
648 	nilfs_btree_free_path(path);
649 
650 	return ret;
651 }
652 
nilfs_btree_lookup_contig(const struct nilfs_bmap * btree,__u64 key,__u64 * ptrp,unsigned maxblocks)653 static int nilfs_btree_lookup_contig(const struct nilfs_bmap *btree,
654 				     __u64 key, __u64 *ptrp, unsigned maxblocks)
655 {
656 	struct nilfs_btree_path *path;
657 	struct nilfs_btree_node *node;
658 	struct inode *dat = NULL;
659 	__u64 ptr, ptr2;
660 	sector_t blocknr;
661 	int level = NILFS_BTREE_LEVEL_NODE_MIN;
662 	int ret, cnt, index, maxlevel, ncmax;
663 	struct nilfs_btree_readahead_info p;
664 
665 	path = nilfs_btree_alloc_path();
666 	if (path == NULL)
667 		return -ENOMEM;
668 
669 	ret = nilfs_btree_do_lookup(btree, path, key, &ptr, level, 1);
670 	if (ret < 0)
671 		goto out;
672 
673 	if (NILFS_BMAP_USE_VBN(btree)) {
674 		dat = nilfs_bmap_get_dat(btree);
675 		ret = nilfs_dat_translate(dat, ptr, &blocknr);
676 		if (ret < 0)
677 			goto out;
678 		ptr = blocknr;
679 	}
680 	cnt = 1;
681 	if (cnt == maxblocks)
682 		goto end;
683 
684 	maxlevel = nilfs_btree_height(btree) - 1;
685 	node = nilfs_btree_get_node(btree, path, level, &ncmax);
686 	index = path[level].bp_index + 1;
687 	for (;;) {
688 		while (index < nilfs_btree_node_get_nchildren(node)) {
689 			if (nilfs_btree_node_get_key(node, index) !=
690 			    key + cnt)
691 				goto end;
692 			ptr2 = nilfs_btree_node_get_ptr(node, index, ncmax);
693 			if (dat) {
694 				ret = nilfs_dat_translate(dat, ptr2, &blocknr);
695 				if (ret < 0)
696 					goto out;
697 				ptr2 = blocknr;
698 			}
699 			if (ptr2 != ptr + cnt || ++cnt == maxblocks)
700 				goto end;
701 			index++;
702 			continue;
703 		}
704 		if (level == maxlevel)
705 			break;
706 
707 		/* look-up right sibling node */
708 		p.node = nilfs_btree_get_node(btree, path, level + 1, &p.ncmax);
709 		p.index = path[level + 1].bp_index + 1;
710 		p.max_ra_blocks = 7;
711 		if (p.index >= nilfs_btree_node_get_nchildren(p.node) ||
712 		    nilfs_btree_node_get_key(p.node, p.index) != key + cnt)
713 			break;
714 		ptr2 = nilfs_btree_node_get_ptr(p.node, p.index, p.ncmax);
715 		path[level + 1].bp_index = p.index;
716 
717 		brelse(path[level].bp_bh);
718 		path[level].bp_bh = NULL;
719 
720 		ret = __nilfs_btree_get_block(btree, ptr2, &path[level].bp_bh,
721 					      &p);
722 		if (ret < 0)
723 			goto out;
724 		node = nilfs_btree_get_nonroot_node(path, level);
725 		ncmax = nilfs_btree_nchildren_per_block(btree);
726 		index = 0;
727 		path[level].bp_index = index;
728 	}
729  end:
730 	*ptrp = ptr;
731 	ret = cnt;
732  out:
733 	nilfs_btree_free_path(path);
734 	return ret;
735 }
736 
nilfs_btree_promote_key(struct nilfs_bmap * btree,struct nilfs_btree_path * path,int level,__u64 key)737 static void nilfs_btree_promote_key(struct nilfs_bmap *btree,
738 				    struct nilfs_btree_path *path,
739 				    int level, __u64 key)
740 {
741 	if (level < nilfs_btree_height(btree) - 1) {
742 		do {
743 			nilfs_btree_node_set_key(
744 				nilfs_btree_get_nonroot_node(path, level),
745 				path[level].bp_index, key);
746 			if (!buffer_dirty(path[level].bp_bh))
747 				mark_buffer_dirty(path[level].bp_bh);
748 		} while ((path[level].bp_index == 0) &&
749 			 (++level < nilfs_btree_height(btree) - 1));
750 	}
751 
752 	/* root */
753 	if (level == nilfs_btree_height(btree) - 1) {
754 		nilfs_btree_node_set_key(nilfs_btree_get_root(btree),
755 					 path[level].bp_index, key);
756 	}
757 }
758 
nilfs_btree_do_insert(struct nilfs_bmap * btree,struct nilfs_btree_path * path,int level,__u64 * keyp,__u64 * ptrp)759 static void nilfs_btree_do_insert(struct nilfs_bmap *btree,
760 				  struct nilfs_btree_path *path,
761 				  int level, __u64 *keyp, __u64 *ptrp)
762 {
763 	struct nilfs_btree_node *node;
764 	int ncblk;
765 
766 	if (level < nilfs_btree_height(btree) - 1) {
767 		node = nilfs_btree_get_nonroot_node(path, level);
768 		ncblk = nilfs_btree_nchildren_per_block(btree);
769 		nilfs_btree_node_insert(node, path[level].bp_index,
770 					*keyp, *ptrp, ncblk);
771 		if (!buffer_dirty(path[level].bp_bh))
772 			mark_buffer_dirty(path[level].bp_bh);
773 
774 		if (path[level].bp_index == 0)
775 			nilfs_btree_promote_key(btree, path, level + 1,
776 						nilfs_btree_node_get_key(node,
777 									 0));
778 	} else {
779 		node = nilfs_btree_get_root(btree);
780 		nilfs_btree_node_insert(node, path[level].bp_index,
781 					*keyp, *ptrp,
782 					NILFS_BTREE_ROOT_NCHILDREN_MAX);
783 	}
784 }
785 
nilfs_btree_carry_left(struct nilfs_bmap * btree,struct nilfs_btree_path * path,int level,__u64 * keyp,__u64 * ptrp)786 static void nilfs_btree_carry_left(struct nilfs_bmap *btree,
787 				   struct nilfs_btree_path *path,
788 				   int level, __u64 *keyp, __u64 *ptrp)
789 {
790 	struct nilfs_btree_node *node, *left;
791 	int nchildren, lnchildren, n, move, ncblk;
792 
793 	node = nilfs_btree_get_nonroot_node(path, level);
794 	left = nilfs_btree_get_sib_node(path, level);
795 	nchildren = nilfs_btree_node_get_nchildren(node);
796 	lnchildren = nilfs_btree_node_get_nchildren(left);
797 	ncblk = nilfs_btree_nchildren_per_block(btree);
798 	move = 0;
799 
800 	n = (nchildren + lnchildren + 1) / 2 - lnchildren;
801 	if (n > path[level].bp_index) {
802 		/* move insert point */
803 		n--;
804 		move = 1;
805 	}
806 
807 	nilfs_btree_node_move_left(left, node, n, ncblk, ncblk);
808 
809 	if (!buffer_dirty(path[level].bp_bh))
810 		mark_buffer_dirty(path[level].bp_bh);
811 	if (!buffer_dirty(path[level].bp_sib_bh))
812 		mark_buffer_dirty(path[level].bp_sib_bh);
813 
814 	nilfs_btree_promote_key(btree, path, level + 1,
815 				nilfs_btree_node_get_key(node, 0));
816 
817 	if (move) {
818 		brelse(path[level].bp_bh);
819 		path[level].bp_bh = path[level].bp_sib_bh;
820 		path[level].bp_sib_bh = NULL;
821 		path[level].bp_index += lnchildren;
822 		path[level + 1].bp_index--;
823 	} else {
824 		brelse(path[level].bp_sib_bh);
825 		path[level].bp_sib_bh = NULL;
826 		path[level].bp_index -= n;
827 	}
828 
829 	nilfs_btree_do_insert(btree, path, level, keyp, ptrp);
830 }
831 
nilfs_btree_carry_right(struct nilfs_bmap * btree,struct nilfs_btree_path * path,int level,__u64 * keyp,__u64 * ptrp)832 static void nilfs_btree_carry_right(struct nilfs_bmap *btree,
833 				    struct nilfs_btree_path *path,
834 				    int level, __u64 *keyp, __u64 *ptrp)
835 {
836 	struct nilfs_btree_node *node, *right;
837 	int nchildren, rnchildren, n, move, ncblk;
838 
839 	node = nilfs_btree_get_nonroot_node(path, level);
840 	right = nilfs_btree_get_sib_node(path, level);
841 	nchildren = nilfs_btree_node_get_nchildren(node);
842 	rnchildren = nilfs_btree_node_get_nchildren(right);
843 	ncblk = nilfs_btree_nchildren_per_block(btree);
844 	move = 0;
845 
846 	n = (nchildren + rnchildren + 1) / 2 - rnchildren;
847 	if (n > nchildren - path[level].bp_index) {
848 		/* move insert point */
849 		n--;
850 		move = 1;
851 	}
852 
853 	nilfs_btree_node_move_right(node, right, n, ncblk, ncblk);
854 
855 	if (!buffer_dirty(path[level].bp_bh))
856 		mark_buffer_dirty(path[level].bp_bh);
857 	if (!buffer_dirty(path[level].bp_sib_bh))
858 		mark_buffer_dirty(path[level].bp_sib_bh);
859 
860 	path[level + 1].bp_index++;
861 	nilfs_btree_promote_key(btree, path, level + 1,
862 				nilfs_btree_node_get_key(right, 0));
863 	path[level + 1].bp_index--;
864 
865 	if (move) {
866 		brelse(path[level].bp_bh);
867 		path[level].bp_bh = path[level].bp_sib_bh;
868 		path[level].bp_sib_bh = NULL;
869 		path[level].bp_index -= nilfs_btree_node_get_nchildren(node);
870 		path[level + 1].bp_index++;
871 	} else {
872 		brelse(path[level].bp_sib_bh);
873 		path[level].bp_sib_bh = NULL;
874 	}
875 
876 	nilfs_btree_do_insert(btree, path, level, keyp, ptrp);
877 }
878 
nilfs_btree_split(struct nilfs_bmap * btree,struct nilfs_btree_path * path,int level,__u64 * keyp,__u64 * ptrp)879 static void nilfs_btree_split(struct nilfs_bmap *btree,
880 			      struct nilfs_btree_path *path,
881 			      int level, __u64 *keyp, __u64 *ptrp)
882 {
883 	struct nilfs_btree_node *node, *right;
884 	__u64 newkey;
885 	__u64 newptr;
886 	int nchildren, n, move, ncblk;
887 
888 	node = nilfs_btree_get_nonroot_node(path, level);
889 	right = nilfs_btree_get_sib_node(path, level);
890 	nchildren = nilfs_btree_node_get_nchildren(node);
891 	ncblk = nilfs_btree_nchildren_per_block(btree);
892 	move = 0;
893 
894 	n = (nchildren + 1) / 2;
895 	if (n > nchildren - path[level].bp_index) {
896 		n--;
897 		move = 1;
898 	}
899 
900 	nilfs_btree_node_move_right(node, right, n, ncblk, ncblk);
901 
902 	if (!buffer_dirty(path[level].bp_bh))
903 		mark_buffer_dirty(path[level].bp_bh);
904 	if (!buffer_dirty(path[level].bp_sib_bh))
905 		mark_buffer_dirty(path[level].bp_sib_bh);
906 
907 	newkey = nilfs_btree_node_get_key(right, 0);
908 	newptr = path[level].bp_newreq.bpr_ptr;
909 
910 	if (move) {
911 		path[level].bp_index -= nilfs_btree_node_get_nchildren(node);
912 		nilfs_btree_node_insert(right, path[level].bp_index,
913 					*keyp, *ptrp, ncblk);
914 
915 		*keyp = nilfs_btree_node_get_key(right, 0);
916 		*ptrp = path[level].bp_newreq.bpr_ptr;
917 
918 		brelse(path[level].bp_bh);
919 		path[level].bp_bh = path[level].bp_sib_bh;
920 		path[level].bp_sib_bh = NULL;
921 	} else {
922 		nilfs_btree_do_insert(btree, path, level, keyp, ptrp);
923 
924 		*keyp = nilfs_btree_node_get_key(right, 0);
925 		*ptrp = path[level].bp_newreq.bpr_ptr;
926 
927 		brelse(path[level].bp_sib_bh);
928 		path[level].bp_sib_bh = NULL;
929 	}
930 
931 	path[level + 1].bp_index++;
932 }
933 
nilfs_btree_grow(struct nilfs_bmap * btree,struct nilfs_btree_path * path,int level,__u64 * keyp,__u64 * ptrp)934 static void nilfs_btree_grow(struct nilfs_bmap *btree,
935 			     struct nilfs_btree_path *path,
936 			     int level, __u64 *keyp, __u64 *ptrp)
937 {
938 	struct nilfs_btree_node *root, *child;
939 	int n, ncblk;
940 
941 	root = nilfs_btree_get_root(btree);
942 	child = nilfs_btree_get_sib_node(path, level);
943 	ncblk = nilfs_btree_nchildren_per_block(btree);
944 
945 	n = nilfs_btree_node_get_nchildren(root);
946 
947 	nilfs_btree_node_move_right(root, child, n,
948 				    NILFS_BTREE_ROOT_NCHILDREN_MAX, ncblk);
949 	nilfs_btree_node_set_level(root, level + 1);
950 
951 	if (!buffer_dirty(path[level].bp_sib_bh))
952 		mark_buffer_dirty(path[level].bp_sib_bh);
953 
954 	path[level].bp_bh = path[level].bp_sib_bh;
955 	path[level].bp_sib_bh = NULL;
956 
957 	nilfs_btree_do_insert(btree, path, level, keyp, ptrp);
958 
959 	*keyp = nilfs_btree_node_get_key(child, 0);
960 	*ptrp = path[level].bp_newreq.bpr_ptr;
961 }
962 
nilfs_btree_find_near(const struct nilfs_bmap * btree,const struct nilfs_btree_path * path)963 static __u64 nilfs_btree_find_near(const struct nilfs_bmap *btree,
964 				   const struct nilfs_btree_path *path)
965 {
966 	struct nilfs_btree_node *node;
967 	int level, ncmax;
968 
969 	if (path == NULL)
970 		return NILFS_BMAP_INVALID_PTR;
971 
972 	/* left sibling */
973 	level = NILFS_BTREE_LEVEL_NODE_MIN;
974 	if (path[level].bp_index > 0) {
975 		node = nilfs_btree_get_node(btree, path, level, &ncmax);
976 		return nilfs_btree_node_get_ptr(node,
977 						path[level].bp_index - 1,
978 						ncmax);
979 	}
980 
981 	/* parent */
982 	level = NILFS_BTREE_LEVEL_NODE_MIN + 1;
983 	if (level <= nilfs_btree_height(btree) - 1) {
984 		node = nilfs_btree_get_node(btree, path, level, &ncmax);
985 		return nilfs_btree_node_get_ptr(node, path[level].bp_index,
986 						ncmax);
987 	}
988 
989 	return NILFS_BMAP_INVALID_PTR;
990 }
991 
nilfs_btree_find_target_v(const struct nilfs_bmap * btree,const struct nilfs_btree_path * path,__u64 key)992 static __u64 nilfs_btree_find_target_v(const struct nilfs_bmap *btree,
993 				       const struct nilfs_btree_path *path,
994 				       __u64 key)
995 {
996 	__u64 ptr;
997 
998 	ptr = nilfs_bmap_find_target_seq(btree, key);
999 	if (ptr != NILFS_BMAP_INVALID_PTR)
1000 		/* sequential access */
1001 		return ptr;
1002 	else {
1003 		ptr = nilfs_btree_find_near(btree, path);
1004 		if (ptr != NILFS_BMAP_INVALID_PTR)
1005 			/* near */
1006 			return ptr;
1007 	}
1008 	/* block group */
1009 	return nilfs_bmap_find_target_in_group(btree);
1010 }
1011 
nilfs_btree_prepare_insert(struct nilfs_bmap * btree,struct nilfs_btree_path * path,int * levelp,__u64 key,__u64 ptr,struct nilfs_bmap_stats * stats)1012 static int nilfs_btree_prepare_insert(struct nilfs_bmap *btree,
1013 				      struct nilfs_btree_path *path,
1014 				      int *levelp, __u64 key, __u64 ptr,
1015 				      struct nilfs_bmap_stats *stats)
1016 {
1017 	struct buffer_head *bh;
1018 	struct nilfs_btree_node *node, *parent, *sib;
1019 	__u64 sibptr;
1020 	int pindex, level, ncmax, ncblk, ret;
1021 	struct inode *dat = NULL;
1022 
1023 	stats->bs_nblocks = 0;
1024 	level = NILFS_BTREE_LEVEL_DATA;
1025 
1026 	/* allocate a new ptr for data block */
1027 	if (NILFS_BMAP_USE_VBN(btree)) {
1028 		path[level].bp_newreq.bpr_ptr =
1029 			nilfs_btree_find_target_v(btree, path, key);
1030 		dat = nilfs_bmap_get_dat(btree);
1031 	}
1032 
1033 	ret = nilfs_bmap_prepare_alloc_ptr(btree, &path[level].bp_newreq, dat);
1034 	if (ret < 0)
1035 		goto err_out_data;
1036 
1037 	ncblk = nilfs_btree_nchildren_per_block(btree);
1038 
1039 	for (level = NILFS_BTREE_LEVEL_NODE_MIN;
1040 	     level < nilfs_btree_height(btree) - 1;
1041 	     level++) {
1042 		node = nilfs_btree_get_nonroot_node(path, level);
1043 		if (nilfs_btree_node_get_nchildren(node) < ncblk) {
1044 			path[level].bp_op = nilfs_btree_do_insert;
1045 			stats->bs_nblocks++;
1046 			goto out;
1047 		}
1048 
1049 		parent = nilfs_btree_get_node(btree, path, level + 1, &ncmax);
1050 		pindex = path[level + 1].bp_index;
1051 
1052 		/* left sibling */
1053 		if (pindex > 0) {
1054 			sibptr = nilfs_btree_node_get_ptr(parent, pindex - 1,
1055 							  ncmax);
1056 			ret = nilfs_btree_get_block(btree, sibptr, &bh);
1057 			if (ret < 0)
1058 				goto err_out_child_node;
1059 			sib = (struct nilfs_btree_node *)bh->b_data;
1060 			if (nilfs_btree_node_get_nchildren(sib) < ncblk) {
1061 				path[level].bp_sib_bh = bh;
1062 				path[level].bp_op = nilfs_btree_carry_left;
1063 				stats->bs_nblocks++;
1064 				goto out;
1065 			} else {
1066 				brelse(bh);
1067 			}
1068 		}
1069 
1070 		/* right sibling */
1071 		if (pindex < nilfs_btree_node_get_nchildren(parent) - 1) {
1072 			sibptr = nilfs_btree_node_get_ptr(parent, pindex + 1,
1073 							  ncmax);
1074 			ret = nilfs_btree_get_block(btree, sibptr, &bh);
1075 			if (ret < 0)
1076 				goto err_out_child_node;
1077 			sib = (struct nilfs_btree_node *)bh->b_data;
1078 			if (nilfs_btree_node_get_nchildren(sib) < ncblk) {
1079 				path[level].bp_sib_bh = bh;
1080 				path[level].bp_op = nilfs_btree_carry_right;
1081 				stats->bs_nblocks++;
1082 				goto out;
1083 			} else {
1084 				brelse(bh);
1085 			}
1086 		}
1087 
1088 		/* split */
1089 		path[level].bp_newreq.bpr_ptr =
1090 			path[level - 1].bp_newreq.bpr_ptr + 1;
1091 		ret = nilfs_bmap_prepare_alloc_ptr(btree,
1092 						   &path[level].bp_newreq, dat);
1093 		if (ret < 0)
1094 			goto err_out_child_node;
1095 		ret = nilfs_btree_get_new_block(btree,
1096 						path[level].bp_newreq.bpr_ptr,
1097 						&bh);
1098 		if (ret < 0)
1099 			goto err_out_curr_node;
1100 
1101 		stats->bs_nblocks++;
1102 
1103 		sib = (struct nilfs_btree_node *)bh->b_data;
1104 		nilfs_btree_node_init(sib, 0, level, 0, ncblk, NULL, NULL);
1105 		path[level].bp_sib_bh = bh;
1106 		path[level].bp_op = nilfs_btree_split;
1107 	}
1108 
1109 	/* root */
1110 	node = nilfs_btree_get_root(btree);
1111 	if (nilfs_btree_node_get_nchildren(node) <
1112 	    NILFS_BTREE_ROOT_NCHILDREN_MAX) {
1113 		path[level].bp_op = nilfs_btree_do_insert;
1114 		stats->bs_nblocks++;
1115 		goto out;
1116 	}
1117 
1118 	/* grow */
1119 	path[level].bp_newreq.bpr_ptr = path[level - 1].bp_newreq.bpr_ptr + 1;
1120 	ret = nilfs_bmap_prepare_alloc_ptr(btree, &path[level].bp_newreq, dat);
1121 	if (ret < 0)
1122 		goto err_out_child_node;
1123 	ret = nilfs_btree_get_new_block(btree, path[level].bp_newreq.bpr_ptr,
1124 					&bh);
1125 	if (ret < 0)
1126 		goto err_out_curr_node;
1127 
1128 	nilfs_btree_node_init((struct nilfs_btree_node *)bh->b_data,
1129 			      0, level, 0, ncblk, NULL, NULL);
1130 	path[level].bp_sib_bh = bh;
1131 	path[level].bp_op = nilfs_btree_grow;
1132 
1133 	level++;
1134 	path[level].bp_op = nilfs_btree_do_insert;
1135 
1136 	/* a newly-created node block and a data block are added */
1137 	stats->bs_nblocks += 2;
1138 
1139 	/* success */
1140  out:
1141 	*levelp = level;
1142 	return ret;
1143 
1144 	/* error */
1145  err_out_curr_node:
1146 	nilfs_bmap_abort_alloc_ptr(btree, &path[level].bp_newreq, dat);
1147  err_out_child_node:
1148 	for (level--; level > NILFS_BTREE_LEVEL_DATA; level--) {
1149 		nilfs_btnode_delete(path[level].bp_sib_bh);
1150 		nilfs_bmap_abort_alloc_ptr(btree, &path[level].bp_newreq, dat);
1151 
1152 	}
1153 
1154 	nilfs_bmap_abort_alloc_ptr(btree, &path[level].bp_newreq, dat);
1155  err_out_data:
1156 	*levelp = level;
1157 	stats->bs_nblocks = 0;
1158 	return ret;
1159 }
1160 
nilfs_btree_commit_insert(struct nilfs_bmap * btree,struct nilfs_btree_path * path,int maxlevel,__u64 key,__u64 ptr)1161 static void nilfs_btree_commit_insert(struct nilfs_bmap *btree,
1162 				      struct nilfs_btree_path *path,
1163 				      int maxlevel, __u64 key, __u64 ptr)
1164 {
1165 	struct inode *dat = NULL;
1166 	int level;
1167 
1168 	set_buffer_nilfs_volatile((struct buffer_head *)((unsigned long)ptr));
1169 	ptr = path[NILFS_BTREE_LEVEL_DATA].bp_newreq.bpr_ptr;
1170 	if (NILFS_BMAP_USE_VBN(btree)) {
1171 		nilfs_bmap_set_target_v(btree, key, ptr);
1172 		dat = nilfs_bmap_get_dat(btree);
1173 	}
1174 
1175 	for (level = NILFS_BTREE_LEVEL_NODE_MIN; level <= maxlevel; level++) {
1176 		nilfs_bmap_commit_alloc_ptr(btree,
1177 					    &path[level - 1].bp_newreq, dat);
1178 		path[level].bp_op(btree, path, level, &key, &ptr);
1179 	}
1180 
1181 	if (!nilfs_bmap_dirty(btree))
1182 		nilfs_bmap_set_dirty(btree);
1183 }
1184 
nilfs_btree_insert(struct nilfs_bmap * btree,__u64 key,__u64 ptr)1185 static int nilfs_btree_insert(struct nilfs_bmap *btree, __u64 key, __u64 ptr)
1186 {
1187 	struct nilfs_btree_path *path;
1188 	struct nilfs_bmap_stats stats;
1189 	int level, ret;
1190 
1191 	path = nilfs_btree_alloc_path();
1192 	if (path == NULL)
1193 		return -ENOMEM;
1194 
1195 	ret = nilfs_btree_do_lookup(btree, path, key, NULL,
1196 				    NILFS_BTREE_LEVEL_NODE_MIN, 0);
1197 	if (ret != -ENOENT) {
1198 		if (ret == 0)
1199 			ret = -EEXIST;
1200 		goto out;
1201 	}
1202 
1203 	ret = nilfs_btree_prepare_insert(btree, path, &level, key, ptr, &stats);
1204 	if (ret < 0)
1205 		goto out;
1206 	nilfs_btree_commit_insert(btree, path, level, key, ptr);
1207 	nilfs_inode_add_blocks(btree->b_inode, stats.bs_nblocks);
1208 
1209  out:
1210 	nilfs_btree_free_path(path);
1211 	return ret;
1212 }
1213 
nilfs_btree_do_delete(struct nilfs_bmap * btree,struct nilfs_btree_path * path,int level,__u64 * keyp,__u64 * ptrp)1214 static void nilfs_btree_do_delete(struct nilfs_bmap *btree,
1215 				  struct nilfs_btree_path *path,
1216 				  int level, __u64 *keyp, __u64 *ptrp)
1217 {
1218 	struct nilfs_btree_node *node;
1219 	int ncblk;
1220 
1221 	if (level < nilfs_btree_height(btree) - 1) {
1222 		node = nilfs_btree_get_nonroot_node(path, level);
1223 		ncblk = nilfs_btree_nchildren_per_block(btree);
1224 		nilfs_btree_node_delete(node, path[level].bp_index,
1225 					keyp, ptrp, ncblk);
1226 		if (!buffer_dirty(path[level].bp_bh))
1227 			mark_buffer_dirty(path[level].bp_bh);
1228 		if (path[level].bp_index == 0)
1229 			nilfs_btree_promote_key(btree, path, level + 1,
1230 				nilfs_btree_node_get_key(node, 0));
1231 	} else {
1232 		node = nilfs_btree_get_root(btree);
1233 		nilfs_btree_node_delete(node, path[level].bp_index,
1234 					keyp, ptrp,
1235 					NILFS_BTREE_ROOT_NCHILDREN_MAX);
1236 	}
1237 }
1238 
nilfs_btree_borrow_left(struct nilfs_bmap * btree,struct nilfs_btree_path * path,int level,__u64 * keyp,__u64 * ptrp)1239 static void nilfs_btree_borrow_left(struct nilfs_bmap *btree,
1240 				    struct nilfs_btree_path *path,
1241 				    int level, __u64 *keyp, __u64 *ptrp)
1242 {
1243 	struct nilfs_btree_node *node, *left;
1244 	int nchildren, lnchildren, n, ncblk;
1245 
1246 	nilfs_btree_do_delete(btree, path, level, keyp, ptrp);
1247 
1248 	node = nilfs_btree_get_nonroot_node(path, level);
1249 	left = nilfs_btree_get_sib_node(path, level);
1250 	nchildren = nilfs_btree_node_get_nchildren(node);
1251 	lnchildren = nilfs_btree_node_get_nchildren(left);
1252 	ncblk = nilfs_btree_nchildren_per_block(btree);
1253 
1254 	n = (nchildren + lnchildren) / 2 - nchildren;
1255 
1256 	nilfs_btree_node_move_right(left, node, n, ncblk, ncblk);
1257 
1258 	if (!buffer_dirty(path[level].bp_bh))
1259 		mark_buffer_dirty(path[level].bp_bh);
1260 	if (!buffer_dirty(path[level].bp_sib_bh))
1261 		mark_buffer_dirty(path[level].bp_sib_bh);
1262 
1263 	nilfs_btree_promote_key(btree, path, level + 1,
1264 				nilfs_btree_node_get_key(node, 0));
1265 
1266 	brelse(path[level].bp_sib_bh);
1267 	path[level].bp_sib_bh = NULL;
1268 	path[level].bp_index += n;
1269 }
1270 
nilfs_btree_borrow_right(struct nilfs_bmap * btree,struct nilfs_btree_path * path,int level,__u64 * keyp,__u64 * ptrp)1271 static void nilfs_btree_borrow_right(struct nilfs_bmap *btree,
1272 				     struct nilfs_btree_path *path,
1273 				     int level, __u64 *keyp, __u64 *ptrp)
1274 {
1275 	struct nilfs_btree_node *node, *right;
1276 	int nchildren, rnchildren, n, ncblk;
1277 
1278 	nilfs_btree_do_delete(btree, path, level, keyp, ptrp);
1279 
1280 	node = nilfs_btree_get_nonroot_node(path, level);
1281 	right = nilfs_btree_get_sib_node(path, level);
1282 	nchildren = nilfs_btree_node_get_nchildren(node);
1283 	rnchildren = nilfs_btree_node_get_nchildren(right);
1284 	ncblk = nilfs_btree_nchildren_per_block(btree);
1285 
1286 	n = (nchildren + rnchildren) / 2 - nchildren;
1287 
1288 	nilfs_btree_node_move_left(node, right, 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 	path[level + 1].bp_index++;
1296 	nilfs_btree_promote_key(btree, path, level + 1,
1297 				nilfs_btree_node_get_key(right, 0));
1298 	path[level + 1].bp_index--;
1299 
1300 	brelse(path[level].bp_sib_bh);
1301 	path[level].bp_sib_bh = NULL;
1302 }
1303 
nilfs_btree_concat_left(struct nilfs_bmap * btree,struct nilfs_btree_path * path,int level,__u64 * keyp,__u64 * ptrp)1304 static void nilfs_btree_concat_left(struct nilfs_bmap *btree,
1305 				    struct nilfs_btree_path *path,
1306 				    int level, __u64 *keyp, __u64 *ptrp)
1307 {
1308 	struct nilfs_btree_node *node, *left;
1309 	int n, ncblk;
1310 
1311 	nilfs_btree_do_delete(btree, path, level, keyp, ptrp);
1312 
1313 	node = nilfs_btree_get_nonroot_node(path, level);
1314 	left = nilfs_btree_get_sib_node(path, level);
1315 	ncblk = nilfs_btree_nchildren_per_block(btree);
1316 
1317 	n = nilfs_btree_node_get_nchildren(node);
1318 
1319 	nilfs_btree_node_move_left(left, node, n, ncblk, ncblk);
1320 
1321 	if (!buffer_dirty(path[level].bp_sib_bh))
1322 		mark_buffer_dirty(path[level].bp_sib_bh);
1323 
1324 	nilfs_btnode_delete(path[level].bp_bh);
1325 	path[level].bp_bh = path[level].bp_sib_bh;
1326 	path[level].bp_sib_bh = NULL;
1327 	path[level].bp_index += nilfs_btree_node_get_nchildren(left);
1328 }
1329 
nilfs_btree_concat_right(struct nilfs_bmap * btree,struct nilfs_btree_path * path,int level,__u64 * keyp,__u64 * ptrp)1330 static void nilfs_btree_concat_right(struct nilfs_bmap *btree,
1331 				     struct nilfs_btree_path *path,
1332 				     int level, __u64 *keyp, __u64 *ptrp)
1333 {
1334 	struct nilfs_btree_node *node, *right;
1335 	int n, ncblk;
1336 
1337 	nilfs_btree_do_delete(btree, path, level, keyp, ptrp);
1338 
1339 	node = nilfs_btree_get_nonroot_node(path, level);
1340 	right = nilfs_btree_get_sib_node(path, level);
1341 	ncblk = nilfs_btree_nchildren_per_block(btree);
1342 
1343 	n = nilfs_btree_node_get_nchildren(right);
1344 
1345 	nilfs_btree_node_move_left(node, right, n, ncblk, ncblk);
1346 
1347 	if (!buffer_dirty(path[level].bp_bh))
1348 		mark_buffer_dirty(path[level].bp_bh);
1349 
1350 	nilfs_btnode_delete(path[level].bp_sib_bh);
1351 	path[level].bp_sib_bh = NULL;
1352 	path[level + 1].bp_index++;
1353 }
1354 
nilfs_btree_shrink(struct nilfs_bmap * btree,struct nilfs_btree_path * path,int level,__u64 * keyp,__u64 * ptrp)1355 static void nilfs_btree_shrink(struct nilfs_bmap *btree,
1356 			       struct nilfs_btree_path *path,
1357 			       int level, __u64 *keyp, __u64 *ptrp)
1358 {
1359 	struct nilfs_btree_node *root, *child;
1360 	int n, ncblk;
1361 
1362 	nilfs_btree_do_delete(btree, path, level, keyp, ptrp);
1363 
1364 	root = nilfs_btree_get_root(btree);
1365 	child = nilfs_btree_get_nonroot_node(path, level);
1366 	ncblk = nilfs_btree_nchildren_per_block(btree);
1367 
1368 	nilfs_btree_node_delete(root, 0, NULL, NULL,
1369 				NILFS_BTREE_ROOT_NCHILDREN_MAX);
1370 	nilfs_btree_node_set_level(root, level);
1371 	n = nilfs_btree_node_get_nchildren(child);
1372 	nilfs_btree_node_move_left(root, child, n,
1373 				   NILFS_BTREE_ROOT_NCHILDREN_MAX, ncblk);
1374 
1375 	nilfs_btnode_delete(path[level].bp_bh);
1376 	path[level].bp_bh = NULL;
1377 }
1378 
nilfs_btree_nop(struct nilfs_bmap * btree,struct nilfs_btree_path * path,int level,__u64 * keyp,__u64 * ptrp)1379 static void nilfs_btree_nop(struct nilfs_bmap *btree,
1380 			    struct nilfs_btree_path *path,
1381 			    int level, __u64 *keyp, __u64 *ptrp)
1382 {
1383 }
1384 
nilfs_btree_prepare_delete(struct nilfs_bmap * btree,struct nilfs_btree_path * path,int * levelp,struct nilfs_bmap_stats * stats,struct inode * dat)1385 static int nilfs_btree_prepare_delete(struct nilfs_bmap *btree,
1386 				      struct nilfs_btree_path *path,
1387 				      int *levelp,
1388 				      struct nilfs_bmap_stats *stats,
1389 				      struct inode *dat)
1390 {
1391 	struct buffer_head *bh;
1392 	struct nilfs_btree_node *node, *parent, *sib;
1393 	__u64 sibptr;
1394 	int pindex, dindex, level, ncmin, ncmax, ncblk, ret;
1395 
1396 	ret = 0;
1397 	stats->bs_nblocks = 0;
1398 	ncmin = NILFS_BTREE_NODE_NCHILDREN_MIN(nilfs_btree_node_size(btree));
1399 	ncblk = nilfs_btree_nchildren_per_block(btree);
1400 
1401 	for (level = NILFS_BTREE_LEVEL_NODE_MIN, dindex = path[level].bp_index;
1402 	     level < nilfs_btree_height(btree) - 1;
1403 	     level++) {
1404 		node = nilfs_btree_get_nonroot_node(path, level);
1405 		path[level].bp_oldreq.bpr_ptr =
1406 			nilfs_btree_node_get_ptr(node, dindex, ncblk);
1407 		ret = nilfs_bmap_prepare_end_ptr(btree,
1408 						 &path[level].bp_oldreq, dat);
1409 		if (ret < 0)
1410 			goto err_out_child_node;
1411 
1412 		if (nilfs_btree_node_get_nchildren(node) > ncmin) {
1413 			path[level].bp_op = nilfs_btree_do_delete;
1414 			stats->bs_nblocks++;
1415 			goto out;
1416 		}
1417 
1418 		parent = nilfs_btree_get_node(btree, path, level + 1, &ncmax);
1419 		pindex = path[level + 1].bp_index;
1420 		dindex = pindex;
1421 
1422 		if (pindex > 0) {
1423 			/* left sibling */
1424 			sibptr = nilfs_btree_node_get_ptr(parent, pindex - 1,
1425 							  ncmax);
1426 			ret = nilfs_btree_get_block(btree, sibptr, &bh);
1427 			if (ret < 0)
1428 				goto err_out_curr_node;
1429 			sib = (struct nilfs_btree_node *)bh->b_data;
1430 			if (nilfs_btree_node_get_nchildren(sib) > ncmin) {
1431 				path[level].bp_sib_bh = bh;
1432 				path[level].bp_op = nilfs_btree_borrow_left;
1433 				stats->bs_nblocks++;
1434 				goto out;
1435 			} else {
1436 				path[level].bp_sib_bh = bh;
1437 				path[level].bp_op = nilfs_btree_concat_left;
1438 				stats->bs_nblocks++;
1439 				/* continue; */
1440 			}
1441 		} else if (pindex <
1442 			   nilfs_btree_node_get_nchildren(parent) - 1) {
1443 			/* right sibling */
1444 			sibptr = nilfs_btree_node_get_ptr(parent, pindex + 1,
1445 							  ncmax);
1446 			ret = nilfs_btree_get_block(btree, sibptr, &bh);
1447 			if (ret < 0)
1448 				goto err_out_curr_node;
1449 			sib = (struct nilfs_btree_node *)bh->b_data;
1450 			if (nilfs_btree_node_get_nchildren(sib) > ncmin) {
1451 				path[level].bp_sib_bh = bh;
1452 				path[level].bp_op = nilfs_btree_borrow_right;
1453 				stats->bs_nblocks++;
1454 				goto out;
1455 			} else {
1456 				path[level].bp_sib_bh = bh;
1457 				path[level].bp_op = nilfs_btree_concat_right;
1458 				stats->bs_nblocks++;
1459 				/*
1460 				 * When merging right sibling node
1461 				 * into the current node, pointer to
1462 				 * the right sibling node must be
1463 				 * terminated instead.  The adjustment
1464 				 * below is required for that.
1465 				 */
1466 				dindex = pindex + 1;
1467 				/* continue; */
1468 			}
1469 		} else {
1470 			/* no siblings */
1471 			/* the only child of the root node */
1472 			WARN_ON(level != nilfs_btree_height(btree) - 2);
1473 			if (nilfs_btree_node_get_nchildren(node) - 1 <=
1474 			    NILFS_BTREE_ROOT_NCHILDREN_MAX) {
1475 				path[level].bp_op = nilfs_btree_shrink;
1476 				stats->bs_nblocks += 2;
1477 				level++;
1478 				path[level].bp_op = nilfs_btree_nop;
1479 				goto shrink_root_child;
1480 			} else {
1481 				path[level].bp_op = nilfs_btree_do_delete;
1482 				stats->bs_nblocks++;
1483 				goto out;
1484 			}
1485 		}
1486 	}
1487 
1488 	/* child of the root node is deleted */
1489 	path[level].bp_op = nilfs_btree_do_delete;
1490 	stats->bs_nblocks++;
1491 
1492 shrink_root_child:
1493 	node = nilfs_btree_get_root(btree);
1494 	path[level].bp_oldreq.bpr_ptr =
1495 		nilfs_btree_node_get_ptr(node, dindex,
1496 					 NILFS_BTREE_ROOT_NCHILDREN_MAX);
1497 
1498 	ret = nilfs_bmap_prepare_end_ptr(btree, &path[level].bp_oldreq, dat);
1499 	if (ret < 0)
1500 		goto err_out_child_node;
1501 
1502 	/* success */
1503  out:
1504 	*levelp = level;
1505 	return ret;
1506 
1507 	/* error */
1508  err_out_curr_node:
1509 	nilfs_bmap_abort_end_ptr(btree, &path[level].bp_oldreq, dat);
1510  err_out_child_node:
1511 	for (level--; level >= NILFS_BTREE_LEVEL_NODE_MIN; level--) {
1512 		brelse(path[level].bp_sib_bh);
1513 		nilfs_bmap_abort_end_ptr(btree, &path[level].bp_oldreq, dat);
1514 	}
1515 	*levelp = level;
1516 	stats->bs_nblocks = 0;
1517 	return ret;
1518 }
1519 
nilfs_btree_commit_delete(struct nilfs_bmap * btree,struct nilfs_btree_path * path,int maxlevel,struct inode * dat)1520 static void nilfs_btree_commit_delete(struct nilfs_bmap *btree,
1521 				      struct nilfs_btree_path *path,
1522 				      int maxlevel, struct inode *dat)
1523 {
1524 	int level;
1525 
1526 	for (level = NILFS_BTREE_LEVEL_NODE_MIN; level <= maxlevel; level++) {
1527 		nilfs_bmap_commit_end_ptr(btree, &path[level].bp_oldreq, dat);
1528 		path[level].bp_op(btree, path, level, NULL, NULL);
1529 	}
1530 
1531 	if (!nilfs_bmap_dirty(btree))
1532 		nilfs_bmap_set_dirty(btree);
1533 }
1534 
nilfs_btree_delete(struct nilfs_bmap * btree,__u64 key)1535 static int nilfs_btree_delete(struct nilfs_bmap *btree, __u64 key)
1536 
1537 {
1538 	struct nilfs_btree_path *path;
1539 	struct nilfs_bmap_stats stats;
1540 	struct inode *dat;
1541 	int level, ret;
1542 
1543 	path = nilfs_btree_alloc_path();
1544 	if (path == NULL)
1545 		return -ENOMEM;
1546 
1547 	ret = nilfs_btree_do_lookup(btree, path, key, NULL,
1548 				    NILFS_BTREE_LEVEL_NODE_MIN, 0);
1549 	if (ret < 0)
1550 		goto out;
1551 
1552 
1553 	dat = NILFS_BMAP_USE_VBN(btree) ? nilfs_bmap_get_dat(btree) : NULL;
1554 
1555 	ret = nilfs_btree_prepare_delete(btree, path, &level, &stats, dat);
1556 	if (ret < 0)
1557 		goto out;
1558 	nilfs_btree_commit_delete(btree, path, level, dat);
1559 	nilfs_inode_sub_blocks(btree->b_inode, stats.bs_nblocks);
1560 
1561 out:
1562 	nilfs_btree_free_path(path);
1563 	return ret;
1564 }
1565 
nilfs_btree_last_key(const struct nilfs_bmap * btree,__u64 * keyp)1566 static int nilfs_btree_last_key(const struct nilfs_bmap *btree, __u64 *keyp)
1567 {
1568 	struct nilfs_btree_path *path;
1569 	int ret;
1570 
1571 	path = nilfs_btree_alloc_path();
1572 	if (path == NULL)
1573 		return -ENOMEM;
1574 
1575 	ret = nilfs_btree_do_lookup_last(btree, path, keyp, NULL);
1576 
1577 	nilfs_btree_free_path(path);
1578 
1579 	return ret;
1580 }
1581 
nilfs_btree_check_delete(struct nilfs_bmap * btree,__u64 key)1582 static int nilfs_btree_check_delete(struct nilfs_bmap *btree, __u64 key)
1583 {
1584 	struct buffer_head *bh;
1585 	struct nilfs_btree_node *root, *node;
1586 	__u64 maxkey, nextmaxkey;
1587 	__u64 ptr;
1588 	int nchildren, ret;
1589 
1590 	root = nilfs_btree_get_root(btree);
1591 	switch (nilfs_btree_height(btree)) {
1592 	case 2:
1593 		bh = NULL;
1594 		node = root;
1595 		break;
1596 	case 3:
1597 		nchildren = nilfs_btree_node_get_nchildren(root);
1598 		if (nchildren > 1)
1599 			return 0;
1600 		ptr = nilfs_btree_node_get_ptr(root, nchildren - 1,
1601 					       NILFS_BTREE_ROOT_NCHILDREN_MAX);
1602 		ret = nilfs_btree_get_block(btree, ptr, &bh);
1603 		if (ret < 0)
1604 			return ret;
1605 		node = (struct nilfs_btree_node *)bh->b_data;
1606 		break;
1607 	default:
1608 		return 0;
1609 	}
1610 
1611 	nchildren = nilfs_btree_node_get_nchildren(node);
1612 	maxkey = nilfs_btree_node_get_key(node, nchildren - 1);
1613 	nextmaxkey = (nchildren > 1) ?
1614 		nilfs_btree_node_get_key(node, nchildren - 2) : 0;
1615 	if (bh != NULL)
1616 		brelse(bh);
1617 
1618 	return (maxkey == key) && (nextmaxkey < NILFS_BMAP_LARGE_LOW);
1619 }
1620 
nilfs_btree_gather_data(struct nilfs_bmap * btree,__u64 * keys,__u64 * ptrs,int nitems)1621 static int nilfs_btree_gather_data(struct nilfs_bmap *btree,
1622 				   __u64 *keys, __u64 *ptrs, int nitems)
1623 {
1624 	struct buffer_head *bh;
1625 	struct nilfs_btree_node *node, *root;
1626 	__le64 *dkeys;
1627 	__le64 *dptrs;
1628 	__u64 ptr;
1629 	int nchildren, ncmax, i, ret;
1630 
1631 	root = nilfs_btree_get_root(btree);
1632 	switch (nilfs_btree_height(btree)) {
1633 	case 2:
1634 		bh = NULL;
1635 		node = root;
1636 		ncmax = NILFS_BTREE_ROOT_NCHILDREN_MAX;
1637 		break;
1638 	case 3:
1639 		nchildren = nilfs_btree_node_get_nchildren(root);
1640 		WARN_ON(nchildren > 1);
1641 		ptr = nilfs_btree_node_get_ptr(root, nchildren - 1,
1642 					       NILFS_BTREE_ROOT_NCHILDREN_MAX);
1643 		ret = nilfs_btree_get_block(btree, ptr, &bh);
1644 		if (ret < 0)
1645 			return ret;
1646 		node = (struct nilfs_btree_node *)bh->b_data;
1647 		ncmax = nilfs_btree_nchildren_per_block(btree);
1648 		break;
1649 	default:
1650 		node = NULL;
1651 		return -EINVAL;
1652 	}
1653 
1654 	nchildren = nilfs_btree_node_get_nchildren(node);
1655 	if (nchildren < nitems)
1656 		nitems = nchildren;
1657 	dkeys = nilfs_btree_node_dkeys(node);
1658 	dptrs = nilfs_btree_node_dptrs(node, ncmax);
1659 	for (i = 0; i < nitems; i++) {
1660 		keys[i] = le64_to_cpu(dkeys[i]);
1661 		ptrs[i] = le64_to_cpu(dptrs[i]);
1662 	}
1663 
1664 	if (bh != NULL)
1665 		brelse(bh);
1666 
1667 	return nitems;
1668 }
1669 
1670 static int
nilfs_btree_prepare_convert_and_insert(struct nilfs_bmap * btree,__u64 key,union nilfs_bmap_ptr_req * dreq,union nilfs_bmap_ptr_req * nreq,struct buffer_head ** bhp,struct nilfs_bmap_stats * stats)1671 nilfs_btree_prepare_convert_and_insert(struct nilfs_bmap *btree, __u64 key,
1672 				       union nilfs_bmap_ptr_req *dreq,
1673 				       union nilfs_bmap_ptr_req *nreq,
1674 				       struct buffer_head **bhp,
1675 				       struct nilfs_bmap_stats *stats)
1676 {
1677 	struct buffer_head *bh;
1678 	struct inode *dat = NULL;
1679 	int ret;
1680 
1681 	stats->bs_nblocks = 0;
1682 
1683 	/* for data */
1684 	/* cannot find near ptr */
1685 	if (NILFS_BMAP_USE_VBN(btree)) {
1686 		dreq->bpr_ptr = nilfs_btree_find_target_v(btree, NULL, key);
1687 		dat = nilfs_bmap_get_dat(btree);
1688 	}
1689 
1690 	ret = nilfs_bmap_prepare_alloc_ptr(btree, dreq, dat);
1691 	if (ret < 0)
1692 		return ret;
1693 
1694 	*bhp = NULL;
1695 	stats->bs_nblocks++;
1696 	if (nreq != NULL) {
1697 		nreq->bpr_ptr = dreq->bpr_ptr + 1;
1698 		ret = nilfs_bmap_prepare_alloc_ptr(btree, nreq, dat);
1699 		if (ret < 0)
1700 			goto err_out_dreq;
1701 
1702 		ret = nilfs_btree_get_new_block(btree, nreq->bpr_ptr, &bh);
1703 		if (ret < 0)
1704 			goto err_out_nreq;
1705 
1706 		*bhp = bh;
1707 		stats->bs_nblocks++;
1708 	}
1709 
1710 	/* success */
1711 	return 0;
1712 
1713 	/* error */
1714  err_out_nreq:
1715 	nilfs_bmap_abort_alloc_ptr(btree, nreq, dat);
1716  err_out_dreq:
1717 	nilfs_bmap_abort_alloc_ptr(btree, dreq, dat);
1718 	stats->bs_nblocks = 0;
1719 	return ret;
1720 
1721 }
1722 
1723 static void
nilfs_btree_commit_convert_and_insert(struct nilfs_bmap * btree,__u64 key,__u64 ptr,const __u64 * keys,const __u64 * ptrs,int n,union nilfs_bmap_ptr_req * dreq,union nilfs_bmap_ptr_req * nreq,struct buffer_head * bh)1724 nilfs_btree_commit_convert_and_insert(struct nilfs_bmap *btree,
1725 				      __u64 key, __u64 ptr,
1726 				      const __u64 *keys, const __u64 *ptrs,
1727 				      int n,
1728 				      union nilfs_bmap_ptr_req *dreq,
1729 				      union nilfs_bmap_ptr_req *nreq,
1730 				      struct buffer_head *bh)
1731 {
1732 	struct nilfs_btree_node *node;
1733 	struct inode *dat;
1734 	__u64 tmpptr;
1735 	int ncblk;
1736 
1737 	/* free resources */
1738 	if (btree->b_ops->bop_clear != NULL)
1739 		btree->b_ops->bop_clear(btree);
1740 
1741 	/* ptr must be a pointer to a buffer head. */
1742 	set_buffer_nilfs_volatile((struct buffer_head *)((unsigned long)ptr));
1743 
1744 	/* convert and insert */
1745 	dat = NILFS_BMAP_USE_VBN(btree) ? nilfs_bmap_get_dat(btree) : NULL;
1746 	__nilfs_btree_init(btree);
1747 	if (nreq != NULL) {
1748 		nilfs_bmap_commit_alloc_ptr(btree, dreq, dat);
1749 		nilfs_bmap_commit_alloc_ptr(btree, nreq, dat);
1750 
1751 		/* create child node at level 1 */
1752 		node = (struct nilfs_btree_node *)bh->b_data;
1753 		ncblk = nilfs_btree_nchildren_per_block(btree);
1754 		nilfs_btree_node_init(node, 0, 1, n, ncblk, keys, ptrs);
1755 		nilfs_btree_node_insert(node, n, key, dreq->bpr_ptr, ncblk);
1756 		if (!buffer_dirty(bh))
1757 			mark_buffer_dirty(bh);
1758 		if (!nilfs_bmap_dirty(btree))
1759 			nilfs_bmap_set_dirty(btree);
1760 
1761 		brelse(bh);
1762 
1763 		/* create root node at level 2 */
1764 		node = nilfs_btree_get_root(btree);
1765 		tmpptr = nreq->bpr_ptr;
1766 		nilfs_btree_node_init(node, NILFS_BTREE_NODE_ROOT, 2, 1,
1767 				      NILFS_BTREE_ROOT_NCHILDREN_MAX,
1768 				      &keys[0], &tmpptr);
1769 	} else {
1770 		nilfs_bmap_commit_alloc_ptr(btree, dreq, dat);
1771 
1772 		/* create root node at level 1 */
1773 		node = nilfs_btree_get_root(btree);
1774 		nilfs_btree_node_init(node, NILFS_BTREE_NODE_ROOT, 1, n,
1775 				      NILFS_BTREE_ROOT_NCHILDREN_MAX,
1776 				      keys, ptrs);
1777 		nilfs_btree_node_insert(node, n, key, dreq->bpr_ptr,
1778 					NILFS_BTREE_ROOT_NCHILDREN_MAX);
1779 		if (!nilfs_bmap_dirty(btree))
1780 			nilfs_bmap_set_dirty(btree);
1781 	}
1782 
1783 	if (NILFS_BMAP_USE_VBN(btree))
1784 		nilfs_bmap_set_target_v(btree, key, dreq->bpr_ptr);
1785 }
1786 
1787 /**
1788  * nilfs_btree_convert_and_insert -
1789  * @bmap:
1790  * @key:
1791  * @ptr:
1792  * @keys:
1793  * @ptrs:
1794  * @n:
1795  */
nilfs_btree_convert_and_insert(struct nilfs_bmap * btree,__u64 key,__u64 ptr,const __u64 * keys,const __u64 * ptrs,int n)1796 int nilfs_btree_convert_and_insert(struct nilfs_bmap *btree,
1797 				   __u64 key, __u64 ptr,
1798 				   const __u64 *keys, const __u64 *ptrs, int n)
1799 {
1800 	struct buffer_head *bh;
1801 	union nilfs_bmap_ptr_req dreq, nreq, *di, *ni;
1802 	struct nilfs_bmap_stats stats;
1803 	int ret;
1804 
1805 	if (n + 1 <= NILFS_BTREE_ROOT_NCHILDREN_MAX) {
1806 		di = &dreq;
1807 		ni = NULL;
1808 	} else if ((n + 1) <= NILFS_BTREE_NODE_NCHILDREN_MAX(
1809 			   1 << btree->b_inode->i_blkbits)) {
1810 		di = &dreq;
1811 		ni = &nreq;
1812 	} else {
1813 		di = NULL;
1814 		ni = NULL;
1815 		BUG();
1816 	}
1817 
1818 	ret = nilfs_btree_prepare_convert_and_insert(btree, key, di, ni, &bh,
1819 						     &stats);
1820 	if (ret < 0)
1821 		return ret;
1822 	nilfs_btree_commit_convert_and_insert(btree, key, ptr, keys, ptrs, n,
1823 					      di, ni, bh);
1824 	nilfs_inode_add_blocks(btree->b_inode, stats.bs_nblocks);
1825 	return 0;
1826 }
1827 
nilfs_btree_propagate_p(struct nilfs_bmap * btree,struct nilfs_btree_path * path,int level,struct buffer_head * bh)1828 static int nilfs_btree_propagate_p(struct nilfs_bmap *btree,
1829 				   struct nilfs_btree_path *path,
1830 				   int level,
1831 				   struct buffer_head *bh)
1832 {
1833 	while ((++level < nilfs_btree_height(btree) - 1) &&
1834 	       !buffer_dirty(path[level].bp_bh))
1835 		mark_buffer_dirty(path[level].bp_bh);
1836 
1837 	return 0;
1838 }
1839 
nilfs_btree_prepare_update_v(struct nilfs_bmap * btree,struct nilfs_btree_path * path,int level,struct inode * dat)1840 static int nilfs_btree_prepare_update_v(struct nilfs_bmap *btree,
1841 					struct nilfs_btree_path *path,
1842 					int level, struct inode *dat)
1843 {
1844 	struct nilfs_btree_node *parent;
1845 	int ncmax, ret;
1846 
1847 	parent = nilfs_btree_get_node(btree, path, level + 1, &ncmax);
1848 	path[level].bp_oldreq.bpr_ptr =
1849 		nilfs_btree_node_get_ptr(parent, path[level + 1].bp_index,
1850 					 ncmax);
1851 	path[level].bp_newreq.bpr_ptr = path[level].bp_oldreq.bpr_ptr + 1;
1852 	ret = nilfs_dat_prepare_update(dat, &path[level].bp_oldreq.bpr_req,
1853 				       &path[level].bp_newreq.bpr_req);
1854 	if (ret < 0)
1855 		return ret;
1856 
1857 	if (buffer_nilfs_node(path[level].bp_bh)) {
1858 		path[level].bp_ctxt.oldkey = path[level].bp_oldreq.bpr_ptr;
1859 		path[level].bp_ctxt.newkey = path[level].bp_newreq.bpr_ptr;
1860 		path[level].bp_ctxt.bh = path[level].bp_bh;
1861 		ret = nilfs_btnode_prepare_change_key(
1862 			&NILFS_BMAP_I(btree)->i_btnode_cache,
1863 			&path[level].bp_ctxt);
1864 		if (ret < 0) {
1865 			nilfs_dat_abort_update(dat,
1866 					       &path[level].bp_oldreq.bpr_req,
1867 					       &path[level].bp_newreq.bpr_req);
1868 			return ret;
1869 		}
1870 	}
1871 
1872 	return 0;
1873 }
1874 
nilfs_btree_commit_update_v(struct nilfs_bmap * btree,struct nilfs_btree_path * path,int level,struct inode * dat)1875 static void nilfs_btree_commit_update_v(struct nilfs_bmap *btree,
1876 					struct nilfs_btree_path *path,
1877 					int level, struct inode *dat)
1878 {
1879 	struct nilfs_btree_node *parent;
1880 	int ncmax;
1881 
1882 	nilfs_dat_commit_update(dat, &path[level].bp_oldreq.bpr_req,
1883 				&path[level].bp_newreq.bpr_req,
1884 				btree->b_ptr_type == NILFS_BMAP_PTR_VS);
1885 
1886 	if (buffer_nilfs_node(path[level].bp_bh)) {
1887 		nilfs_btnode_commit_change_key(
1888 			&NILFS_BMAP_I(btree)->i_btnode_cache,
1889 			&path[level].bp_ctxt);
1890 		path[level].bp_bh = path[level].bp_ctxt.bh;
1891 	}
1892 	set_buffer_nilfs_volatile(path[level].bp_bh);
1893 
1894 	parent = nilfs_btree_get_node(btree, path, level + 1, &ncmax);
1895 	nilfs_btree_node_set_ptr(parent, path[level + 1].bp_index,
1896 				 path[level].bp_newreq.bpr_ptr, ncmax);
1897 }
1898 
nilfs_btree_abort_update_v(struct nilfs_bmap * btree,struct nilfs_btree_path * path,int level,struct inode * dat)1899 static void nilfs_btree_abort_update_v(struct nilfs_bmap *btree,
1900 				       struct nilfs_btree_path *path,
1901 				       int level, struct inode *dat)
1902 {
1903 	nilfs_dat_abort_update(dat, &path[level].bp_oldreq.bpr_req,
1904 			       &path[level].bp_newreq.bpr_req);
1905 	if (buffer_nilfs_node(path[level].bp_bh))
1906 		nilfs_btnode_abort_change_key(
1907 			&NILFS_BMAP_I(btree)->i_btnode_cache,
1908 			&path[level].bp_ctxt);
1909 }
1910 
nilfs_btree_prepare_propagate_v(struct nilfs_bmap * btree,struct nilfs_btree_path * path,int minlevel,int * maxlevelp,struct inode * dat)1911 static int nilfs_btree_prepare_propagate_v(struct nilfs_bmap *btree,
1912 					   struct nilfs_btree_path *path,
1913 					   int minlevel, int *maxlevelp,
1914 					   struct inode *dat)
1915 {
1916 	int level, ret;
1917 
1918 	level = minlevel;
1919 	if (!buffer_nilfs_volatile(path[level].bp_bh)) {
1920 		ret = nilfs_btree_prepare_update_v(btree, path, level, dat);
1921 		if (ret < 0)
1922 			return ret;
1923 	}
1924 	while ((++level < nilfs_btree_height(btree) - 1) &&
1925 	       !buffer_dirty(path[level].bp_bh)) {
1926 
1927 		WARN_ON(buffer_nilfs_volatile(path[level].bp_bh));
1928 		ret = nilfs_btree_prepare_update_v(btree, path, level, dat);
1929 		if (ret < 0)
1930 			goto out;
1931 	}
1932 
1933 	/* success */
1934 	*maxlevelp = level - 1;
1935 	return 0;
1936 
1937 	/* error */
1938  out:
1939 	while (--level > minlevel)
1940 		nilfs_btree_abort_update_v(btree, path, level, dat);
1941 	if (!buffer_nilfs_volatile(path[level].bp_bh))
1942 		nilfs_btree_abort_update_v(btree, path, level, dat);
1943 	return ret;
1944 }
1945 
nilfs_btree_commit_propagate_v(struct nilfs_bmap * btree,struct nilfs_btree_path * path,int minlevel,int maxlevel,struct buffer_head * bh,struct inode * dat)1946 static void nilfs_btree_commit_propagate_v(struct nilfs_bmap *btree,
1947 					   struct nilfs_btree_path *path,
1948 					   int minlevel, int maxlevel,
1949 					   struct buffer_head *bh,
1950 					   struct inode *dat)
1951 {
1952 	int level;
1953 
1954 	if (!buffer_nilfs_volatile(path[minlevel].bp_bh))
1955 		nilfs_btree_commit_update_v(btree, path, minlevel, dat);
1956 
1957 	for (level = minlevel + 1; level <= maxlevel; level++)
1958 		nilfs_btree_commit_update_v(btree, path, level, dat);
1959 }
1960 
nilfs_btree_propagate_v(struct nilfs_bmap * btree,struct nilfs_btree_path * path,int level,struct buffer_head * bh)1961 static int nilfs_btree_propagate_v(struct nilfs_bmap *btree,
1962 				   struct nilfs_btree_path *path,
1963 				   int level, struct buffer_head *bh)
1964 {
1965 	int maxlevel = 0, ret;
1966 	struct nilfs_btree_node *parent;
1967 	struct inode *dat = nilfs_bmap_get_dat(btree);
1968 	__u64 ptr;
1969 	int ncmax;
1970 
1971 	get_bh(bh);
1972 	path[level].bp_bh = bh;
1973 	ret = nilfs_btree_prepare_propagate_v(btree, path, level, &maxlevel,
1974 					      dat);
1975 	if (ret < 0)
1976 		goto out;
1977 
1978 	if (buffer_nilfs_volatile(path[level].bp_bh)) {
1979 		parent = nilfs_btree_get_node(btree, path, level + 1, &ncmax);
1980 		ptr = nilfs_btree_node_get_ptr(parent,
1981 					       path[level + 1].bp_index,
1982 					       ncmax);
1983 		ret = nilfs_dat_mark_dirty(dat, ptr);
1984 		if (ret < 0)
1985 			goto out;
1986 	}
1987 
1988 	nilfs_btree_commit_propagate_v(btree, path, level, maxlevel, bh, dat);
1989 
1990  out:
1991 	brelse(path[level].bp_bh);
1992 	path[level].bp_bh = NULL;
1993 	return ret;
1994 }
1995 
nilfs_btree_propagate(struct nilfs_bmap * btree,struct buffer_head * bh)1996 static int nilfs_btree_propagate(struct nilfs_bmap *btree,
1997 				 struct buffer_head *bh)
1998 {
1999 	struct nilfs_btree_path *path;
2000 	struct nilfs_btree_node *node;
2001 	__u64 key;
2002 	int level, ret;
2003 
2004 	WARN_ON(!buffer_dirty(bh));
2005 
2006 	path = nilfs_btree_alloc_path();
2007 	if (path == NULL)
2008 		return -ENOMEM;
2009 
2010 	if (buffer_nilfs_node(bh)) {
2011 		node = (struct nilfs_btree_node *)bh->b_data;
2012 		key = nilfs_btree_node_get_key(node, 0);
2013 		level = nilfs_btree_node_get_level(node);
2014 	} else {
2015 		key = nilfs_bmap_data_get_key(btree, bh);
2016 		level = NILFS_BTREE_LEVEL_DATA;
2017 	}
2018 
2019 	ret = nilfs_btree_do_lookup(btree, path, key, NULL, level + 1, 0);
2020 	if (ret < 0) {
2021 		if (unlikely(ret == -ENOENT))
2022 			printk(KERN_CRIT "%s: key = %llu, level == %d\n",
2023 			       __func__, (unsigned long long)key, level);
2024 		goto out;
2025 	}
2026 
2027 	ret = NILFS_BMAP_USE_VBN(btree) ?
2028 		nilfs_btree_propagate_v(btree, path, level, bh) :
2029 		nilfs_btree_propagate_p(btree, path, level, bh);
2030 
2031  out:
2032 	nilfs_btree_free_path(path);
2033 
2034 	return ret;
2035 }
2036 
nilfs_btree_propagate_gc(struct nilfs_bmap * btree,struct buffer_head * bh)2037 static int nilfs_btree_propagate_gc(struct nilfs_bmap *btree,
2038 				    struct buffer_head *bh)
2039 {
2040 	return nilfs_dat_mark_dirty(nilfs_bmap_get_dat(btree), bh->b_blocknr);
2041 }
2042 
nilfs_btree_add_dirty_buffer(struct nilfs_bmap * btree,struct list_head * lists,struct buffer_head * bh)2043 static void nilfs_btree_add_dirty_buffer(struct nilfs_bmap *btree,
2044 					 struct list_head *lists,
2045 					 struct buffer_head *bh)
2046 {
2047 	struct list_head *head;
2048 	struct buffer_head *cbh;
2049 	struct nilfs_btree_node *node, *cnode;
2050 	__u64 key, ckey;
2051 	int level;
2052 
2053 	get_bh(bh);
2054 	node = (struct nilfs_btree_node *)bh->b_data;
2055 	key = nilfs_btree_node_get_key(node, 0);
2056 	level = nilfs_btree_node_get_level(node);
2057 	if (level < NILFS_BTREE_LEVEL_NODE_MIN ||
2058 	    level >= NILFS_BTREE_LEVEL_MAX) {
2059 		dump_stack();
2060 		printk(KERN_WARNING
2061 		       "%s: invalid btree level: %d (key=%llu, ino=%lu, "
2062 		       "blocknr=%llu)\n",
2063 		       __func__, level, (unsigned long long)key,
2064 		       NILFS_BMAP_I(btree)->vfs_inode.i_ino,
2065 		       (unsigned long long)bh->b_blocknr);
2066 		return;
2067 	}
2068 
2069 	list_for_each(head, &lists[level]) {
2070 		cbh = list_entry(head, struct buffer_head, b_assoc_buffers);
2071 		cnode = (struct nilfs_btree_node *)cbh->b_data;
2072 		ckey = nilfs_btree_node_get_key(cnode, 0);
2073 		if (key < ckey)
2074 			break;
2075 	}
2076 	list_add_tail(&bh->b_assoc_buffers, head);
2077 }
2078 
nilfs_btree_lookup_dirty_buffers(struct nilfs_bmap * btree,struct list_head * listp)2079 static void nilfs_btree_lookup_dirty_buffers(struct nilfs_bmap *btree,
2080 					     struct list_head *listp)
2081 {
2082 	struct address_space *btcache = &NILFS_BMAP_I(btree)->i_btnode_cache;
2083 	struct list_head lists[NILFS_BTREE_LEVEL_MAX];
2084 	struct pagevec pvec;
2085 	struct buffer_head *bh, *head;
2086 	pgoff_t index = 0;
2087 	int level, i;
2088 
2089 	for (level = NILFS_BTREE_LEVEL_NODE_MIN;
2090 	     level < NILFS_BTREE_LEVEL_MAX;
2091 	     level++)
2092 		INIT_LIST_HEAD(&lists[level]);
2093 
2094 	pagevec_init(&pvec, 0);
2095 
2096 	while (pagevec_lookup_tag(&pvec, btcache, &index, PAGECACHE_TAG_DIRTY,
2097 				  PAGEVEC_SIZE)) {
2098 		for (i = 0; i < pagevec_count(&pvec); i++) {
2099 			bh = head = page_buffers(pvec.pages[i]);
2100 			do {
2101 				if (buffer_dirty(bh))
2102 					nilfs_btree_add_dirty_buffer(btree,
2103 								     lists, bh);
2104 			} while ((bh = bh->b_this_page) != head);
2105 		}
2106 		pagevec_release(&pvec);
2107 		cond_resched();
2108 	}
2109 
2110 	for (level = NILFS_BTREE_LEVEL_NODE_MIN;
2111 	     level < NILFS_BTREE_LEVEL_MAX;
2112 	     level++)
2113 		list_splice_tail(&lists[level], listp);
2114 }
2115 
nilfs_btree_assign_p(struct nilfs_bmap * btree,struct nilfs_btree_path * path,int level,struct buffer_head ** bh,sector_t blocknr,union nilfs_binfo * binfo)2116 static int nilfs_btree_assign_p(struct nilfs_bmap *btree,
2117 				struct nilfs_btree_path *path,
2118 				int level,
2119 				struct buffer_head **bh,
2120 				sector_t blocknr,
2121 				union nilfs_binfo *binfo)
2122 {
2123 	struct nilfs_btree_node *parent;
2124 	__u64 key;
2125 	__u64 ptr;
2126 	int ncmax, ret;
2127 
2128 	parent = nilfs_btree_get_node(btree, path, level + 1, &ncmax);
2129 	ptr = nilfs_btree_node_get_ptr(parent, path[level + 1].bp_index,
2130 				       ncmax);
2131 	if (buffer_nilfs_node(*bh)) {
2132 		path[level].bp_ctxt.oldkey = ptr;
2133 		path[level].bp_ctxt.newkey = blocknr;
2134 		path[level].bp_ctxt.bh = *bh;
2135 		ret = nilfs_btnode_prepare_change_key(
2136 			&NILFS_BMAP_I(btree)->i_btnode_cache,
2137 			&path[level].bp_ctxt);
2138 		if (ret < 0)
2139 			return ret;
2140 		nilfs_btnode_commit_change_key(
2141 			&NILFS_BMAP_I(btree)->i_btnode_cache,
2142 			&path[level].bp_ctxt);
2143 		*bh = path[level].bp_ctxt.bh;
2144 	}
2145 
2146 	nilfs_btree_node_set_ptr(parent, path[level + 1].bp_index, blocknr,
2147 				 ncmax);
2148 
2149 	key = nilfs_btree_node_get_key(parent, path[level + 1].bp_index);
2150 	/* on-disk format */
2151 	binfo->bi_dat.bi_blkoff = cpu_to_le64(key);
2152 	binfo->bi_dat.bi_level = level;
2153 
2154 	return 0;
2155 }
2156 
nilfs_btree_assign_v(struct nilfs_bmap * btree,struct nilfs_btree_path * path,int level,struct buffer_head ** bh,sector_t blocknr,union nilfs_binfo * binfo)2157 static int nilfs_btree_assign_v(struct nilfs_bmap *btree,
2158 				struct nilfs_btree_path *path,
2159 				int level,
2160 				struct buffer_head **bh,
2161 				sector_t blocknr,
2162 				union nilfs_binfo *binfo)
2163 {
2164 	struct nilfs_btree_node *parent;
2165 	struct inode *dat = nilfs_bmap_get_dat(btree);
2166 	__u64 key;
2167 	__u64 ptr;
2168 	union nilfs_bmap_ptr_req req;
2169 	int ncmax, ret;
2170 
2171 	parent = nilfs_btree_get_node(btree, path, level + 1, &ncmax);
2172 	ptr = nilfs_btree_node_get_ptr(parent, path[level + 1].bp_index,
2173 				       ncmax);
2174 	req.bpr_ptr = ptr;
2175 	ret = nilfs_dat_prepare_start(dat, &req.bpr_req);
2176 	if (ret < 0)
2177 		return ret;
2178 	nilfs_dat_commit_start(dat, &req.bpr_req, blocknr);
2179 
2180 	key = nilfs_btree_node_get_key(parent, path[level + 1].bp_index);
2181 	/* on-disk format */
2182 	binfo->bi_v.bi_vblocknr = cpu_to_le64(ptr);
2183 	binfo->bi_v.bi_blkoff = cpu_to_le64(key);
2184 
2185 	return 0;
2186 }
2187 
nilfs_btree_assign(struct nilfs_bmap * btree,struct buffer_head ** bh,sector_t blocknr,union nilfs_binfo * binfo)2188 static int nilfs_btree_assign(struct nilfs_bmap *btree,
2189 			      struct buffer_head **bh,
2190 			      sector_t blocknr,
2191 			      union nilfs_binfo *binfo)
2192 {
2193 	struct nilfs_btree_path *path;
2194 	struct nilfs_btree_node *node;
2195 	__u64 key;
2196 	int level, ret;
2197 
2198 	path = nilfs_btree_alloc_path();
2199 	if (path == NULL)
2200 		return -ENOMEM;
2201 
2202 	if (buffer_nilfs_node(*bh)) {
2203 		node = (struct nilfs_btree_node *)(*bh)->b_data;
2204 		key = nilfs_btree_node_get_key(node, 0);
2205 		level = nilfs_btree_node_get_level(node);
2206 	} else {
2207 		key = nilfs_bmap_data_get_key(btree, *bh);
2208 		level = NILFS_BTREE_LEVEL_DATA;
2209 	}
2210 
2211 	ret = nilfs_btree_do_lookup(btree, path, key, NULL, level + 1, 0);
2212 	if (ret < 0) {
2213 		WARN_ON(ret == -ENOENT);
2214 		goto out;
2215 	}
2216 
2217 	ret = NILFS_BMAP_USE_VBN(btree) ?
2218 		nilfs_btree_assign_v(btree, path, level, bh, blocknr, binfo) :
2219 		nilfs_btree_assign_p(btree, path, level, bh, blocknr, binfo);
2220 
2221  out:
2222 	nilfs_btree_free_path(path);
2223 
2224 	return ret;
2225 }
2226 
nilfs_btree_assign_gc(struct nilfs_bmap * btree,struct buffer_head ** bh,sector_t blocknr,union nilfs_binfo * binfo)2227 static int nilfs_btree_assign_gc(struct nilfs_bmap *btree,
2228 				 struct buffer_head **bh,
2229 				 sector_t blocknr,
2230 				 union nilfs_binfo *binfo)
2231 {
2232 	struct nilfs_btree_node *node;
2233 	__u64 key;
2234 	int ret;
2235 
2236 	ret = nilfs_dat_move(nilfs_bmap_get_dat(btree), (*bh)->b_blocknr,
2237 			     blocknr);
2238 	if (ret < 0)
2239 		return ret;
2240 
2241 	if (buffer_nilfs_node(*bh)) {
2242 		node = (struct nilfs_btree_node *)(*bh)->b_data;
2243 		key = nilfs_btree_node_get_key(node, 0);
2244 	} else
2245 		key = nilfs_bmap_data_get_key(btree, *bh);
2246 
2247 	/* on-disk format */
2248 	binfo->bi_v.bi_vblocknr = cpu_to_le64((*bh)->b_blocknr);
2249 	binfo->bi_v.bi_blkoff = cpu_to_le64(key);
2250 
2251 	return 0;
2252 }
2253 
nilfs_btree_mark(struct nilfs_bmap * btree,__u64 key,int level)2254 static int nilfs_btree_mark(struct nilfs_bmap *btree, __u64 key, int level)
2255 {
2256 	struct buffer_head *bh;
2257 	struct nilfs_btree_path *path;
2258 	__u64 ptr;
2259 	int ret;
2260 
2261 	path = nilfs_btree_alloc_path();
2262 	if (path == NULL)
2263 		return -ENOMEM;
2264 
2265 	ret = nilfs_btree_do_lookup(btree, path, key, &ptr, level + 1, 0);
2266 	if (ret < 0) {
2267 		WARN_ON(ret == -ENOENT);
2268 		goto out;
2269 	}
2270 	ret = nilfs_btree_get_block(btree, ptr, &bh);
2271 	if (ret < 0) {
2272 		WARN_ON(ret == -ENOENT);
2273 		goto out;
2274 	}
2275 
2276 	if (!buffer_dirty(bh))
2277 		mark_buffer_dirty(bh);
2278 	brelse(bh);
2279 	if (!nilfs_bmap_dirty(btree))
2280 		nilfs_bmap_set_dirty(btree);
2281 
2282  out:
2283 	nilfs_btree_free_path(path);
2284 	return ret;
2285 }
2286 
2287 static const struct nilfs_bmap_operations nilfs_btree_ops = {
2288 	.bop_lookup		=	nilfs_btree_lookup,
2289 	.bop_lookup_contig	=	nilfs_btree_lookup_contig,
2290 	.bop_insert		=	nilfs_btree_insert,
2291 	.bop_delete		=	nilfs_btree_delete,
2292 	.bop_clear		=	NULL,
2293 
2294 	.bop_propagate		=	nilfs_btree_propagate,
2295 
2296 	.bop_lookup_dirty_buffers =	nilfs_btree_lookup_dirty_buffers,
2297 
2298 	.bop_assign		=	nilfs_btree_assign,
2299 	.bop_mark		=	nilfs_btree_mark,
2300 
2301 	.bop_last_key		=	nilfs_btree_last_key,
2302 	.bop_check_insert	=	NULL,
2303 	.bop_check_delete	=	nilfs_btree_check_delete,
2304 	.bop_gather_data	=	nilfs_btree_gather_data,
2305 };
2306 
2307 static const struct nilfs_bmap_operations nilfs_btree_ops_gc = {
2308 	.bop_lookup		=	NULL,
2309 	.bop_lookup_contig	=	NULL,
2310 	.bop_insert		=	NULL,
2311 	.bop_delete		=	NULL,
2312 	.bop_clear		=	NULL,
2313 
2314 	.bop_propagate		=	nilfs_btree_propagate_gc,
2315 
2316 	.bop_lookup_dirty_buffers =	nilfs_btree_lookup_dirty_buffers,
2317 
2318 	.bop_assign		=	nilfs_btree_assign_gc,
2319 	.bop_mark		=	NULL,
2320 
2321 	.bop_last_key		=	NULL,
2322 	.bop_check_insert	=	NULL,
2323 	.bop_check_delete	=	NULL,
2324 	.bop_gather_data	=	NULL,
2325 };
2326 
__nilfs_btree_init(struct nilfs_bmap * bmap)2327 static void __nilfs_btree_init(struct nilfs_bmap *bmap)
2328 {
2329 	bmap->b_ops = &nilfs_btree_ops;
2330 	bmap->b_nchildren_per_block =
2331 		NILFS_BTREE_NODE_NCHILDREN_MAX(nilfs_btree_node_size(bmap));
2332 }
2333 
nilfs_btree_init(struct nilfs_bmap * bmap)2334 int nilfs_btree_init(struct nilfs_bmap *bmap)
2335 {
2336 	int ret = 0;
2337 
2338 	__nilfs_btree_init(bmap);
2339 
2340 	if (nilfs_btree_root_broken(nilfs_btree_get_root(bmap),
2341 				    bmap->b_inode->i_ino))
2342 		ret = -EIO;
2343 	return ret;
2344 }
2345 
nilfs_btree_init_gc(struct nilfs_bmap * bmap)2346 void nilfs_btree_init_gc(struct nilfs_bmap *bmap)
2347 {
2348 	bmap->b_ops = &nilfs_btree_ops_gc;
2349 	bmap->b_nchildren_per_block =
2350 		NILFS_BTREE_NODE_NCHILDREN_MAX(nilfs_btree_node_size(bmap));
2351 }
2352