xref: /openbmc/linux/fs/f2fs/extent_cache.c (revision 37744fee)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * f2fs extent cache support
4  *
5  * Copyright (c) 2015 Motorola Mobility
6  * Copyright (c) 2015 Samsung Electronics
7  * Authors: Jaegeuk Kim <jaegeuk@kernel.org>
8  *          Chao Yu <chao2.yu@samsung.com>
9  */
10 
11 #include <linux/fs.h>
12 #include <linux/f2fs_fs.h>
13 
14 #include "f2fs.h"
15 #include "node.h"
16 #include <trace/events/f2fs.h>
17 
18 static struct rb_entry *__lookup_rb_tree_fast(struct rb_entry *cached_re,
19 							unsigned int ofs)
20 {
21 	if (cached_re) {
22 		if (cached_re->ofs <= ofs &&
23 				cached_re->ofs + cached_re->len > ofs) {
24 			return cached_re;
25 		}
26 	}
27 	return NULL;
28 }
29 
30 static struct rb_entry *__lookup_rb_tree_slow(struct rb_root_cached *root,
31 							unsigned int ofs)
32 {
33 	struct rb_node *node = root->rb_root.rb_node;
34 	struct rb_entry *re;
35 
36 	while (node) {
37 		re = rb_entry(node, struct rb_entry, rb_node);
38 
39 		if (ofs < re->ofs)
40 			node = node->rb_left;
41 		else if (ofs >= re->ofs + re->len)
42 			node = node->rb_right;
43 		else
44 			return re;
45 	}
46 	return NULL;
47 }
48 
49 struct rb_entry *f2fs_lookup_rb_tree(struct rb_root_cached *root,
50 				struct rb_entry *cached_re, unsigned int ofs)
51 {
52 	struct rb_entry *re;
53 
54 	re = __lookup_rb_tree_fast(cached_re, ofs);
55 	if (!re)
56 		return __lookup_rb_tree_slow(root, ofs);
57 
58 	return re;
59 }
60 
61 struct rb_node **f2fs_lookup_rb_tree_for_insert(struct f2fs_sb_info *sbi,
62 				struct rb_root_cached *root,
63 				struct rb_node **parent,
64 				unsigned int ofs, bool *leftmost)
65 {
66 	struct rb_node **p = &root->rb_root.rb_node;
67 	struct rb_entry *re;
68 
69 	while (*p) {
70 		*parent = *p;
71 		re = rb_entry(*parent, struct rb_entry, rb_node);
72 
73 		if (ofs < re->ofs) {
74 			p = &(*p)->rb_left;
75 		} else if (ofs >= re->ofs + re->len) {
76 			p = &(*p)->rb_right;
77 			*leftmost = false;
78 		} else {
79 			f2fs_bug_on(sbi, 1);
80 		}
81 	}
82 
83 	return p;
84 }
85 
86 /*
87  * lookup rb entry in position of @ofs in rb-tree,
88  * if hit, return the entry, otherwise, return NULL
89  * @prev_ex: extent before ofs
90  * @next_ex: extent after ofs
91  * @insert_p: insert point for new extent at ofs
92  * in order to simpfy the insertion after.
93  * tree must stay unchanged between lookup and insertion.
94  */
95 struct rb_entry *f2fs_lookup_rb_tree_ret(struct rb_root_cached *root,
96 				struct rb_entry *cached_re,
97 				unsigned int ofs,
98 				struct rb_entry **prev_entry,
99 				struct rb_entry **next_entry,
100 				struct rb_node ***insert_p,
101 				struct rb_node **insert_parent,
102 				bool force, bool *leftmost)
103 {
104 	struct rb_node **pnode = &root->rb_root.rb_node;
105 	struct rb_node *parent = NULL, *tmp_node;
106 	struct rb_entry *re = cached_re;
107 
108 	*insert_p = NULL;
109 	*insert_parent = NULL;
110 	*prev_entry = NULL;
111 	*next_entry = NULL;
112 
113 	if (RB_EMPTY_ROOT(&root->rb_root))
114 		return NULL;
115 
116 	if (re) {
117 		if (re->ofs <= ofs && re->ofs + re->len > ofs)
118 			goto lookup_neighbors;
119 	}
120 
121 	if (leftmost)
122 		*leftmost = true;
123 
124 	while (*pnode) {
125 		parent = *pnode;
126 		re = rb_entry(*pnode, struct rb_entry, rb_node);
127 
128 		if (ofs < re->ofs) {
129 			pnode = &(*pnode)->rb_left;
130 		} else if (ofs >= re->ofs + re->len) {
131 			pnode = &(*pnode)->rb_right;
132 			if (leftmost)
133 				*leftmost = false;
134 		} else {
135 			goto lookup_neighbors;
136 		}
137 	}
138 
139 	*insert_p = pnode;
140 	*insert_parent = parent;
141 
142 	re = rb_entry(parent, struct rb_entry, rb_node);
143 	tmp_node = parent;
144 	if (parent && ofs > re->ofs)
145 		tmp_node = rb_next(parent);
146 	*next_entry = rb_entry_safe(tmp_node, struct rb_entry, rb_node);
147 
148 	tmp_node = parent;
149 	if (parent && ofs < re->ofs)
150 		tmp_node = rb_prev(parent);
151 	*prev_entry = rb_entry_safe(tmp_node, struct rb_entry, rb_node);
152 	return NULL;
153 
154 lookup_neighbors:
155 	if (ofs == re->ofs || force) {
156 		/* lookup prev node for merging backward later */
157 		tmp_node = rb_prev(&re->rb_node);
158 		*prev_entry = rb_entry_safe(tmp_node, struct rb_entry, rb_node);
159 	}
160 	if (ofs == re->ofs + re->len - 1 || force) {
161 		/* lookup next node for merging frontward later */
162 		tmp_node = rb_next(&re->rb_node);
163 		*next_entry = rb_entry_safe(tmp_node, struct rb_entry, rb_node);
164 	}
165 	return re;
166 }
167 
168 bool f2fs_check_rb_tree_consistence(struct f2fs_sb_info *sbi,
169 						struct rb_root_cached *root)
170 {
171 #ifdef CONFIG_F2FS_CHECK_FS
172 	struct rb_node *cur = rb_first_cached(root), *next;
173 	struct rb_entry *cur_re, *next_re;
174 
175 	if (!cur)
176 		return true;
177 
178 	while (cur) {
179 		next = rb_next(cur);
180 		if (!next)
181 			return true;
182 
183 		cur_re = rb_entry(cur, struct rb_entry, rb_node);
184 		next_re = rb_entry(next, struct rb_entry, rb_node);
185 
186 		if (cur_re->ofs + cur_re->len > next_re->ofs) {
187 			f2fs_info(sbi, "inconsistent rbtree, cur(%u, %u) next(%u, %u)",
188 				  cur_re->ofs, cur_re->len,
189 				  next_re->ofs, next_re->len);
190 			return false;
191 		}
192 
193 		cur = next;
194 	}
195 #endif
196 	return true;
197 }
198 
199 static struct kmem_cache *extent_tree_slab;
200 static struct kmem_cache *extent_node_slab;
201 
202 static struct extent_node *__attach_extent_node(struct f2fs_sb_info *sbi,
203 				struct extent_tree *et, struct extent_info *ei,
204 				struct rb_node *parent, struct rb_node **p,
205 				bool leftmost)
206 {
207 	struct extent_node *en;
208 
209 	en = kmem_cache_alloc(extent_node_slab, GFP_ATOMIC);
210 	if (!en)
211 		return NULL;
212 
213 	en->ei = *ei;
214 	INIT_LIST_HEAD(&en->list);
215 	en->et = et;
216 
217 	rb_link_node(&en->rb_node, parent, p);
218 	rb_insert_color_cached(&en->rb_node, &et->root, leftmost);
219 	atomic_inc(&et->node_cnt);
220 	atomic_inc(&sbi->total_ext_node);
221 	return en;
222 }
223 
224 static void __detach_extent_node(struct f2fs_sb_info *sbi,
225 				struct extent_tree *et, struct extent_node *en)
226 {
227 	rb_erase_cached(&en->rb_node, &et->root);
228 	atomic_dec(&et->node_cnt);
229 	atomic_dec(&sbi->total_ext_node);
230 
231 	if (et->cached_en == en)
232 		et->cached_en = NULL;
233 	kmem_cache_free(extent_node_slab, en);
234 }
235 
236 /*
237  * Flow to release an extent_node:
238  * 1. list_del_init
239  * 2. __detach_extent_node
240  * 3. kmem_cache_free.
241  */
242 static void __release_extent_node(struct f2fs_sb_info *sbi,
243 			struct extent_tree *et, struct extent_node *en)
244 {
245 	spin_lock(&sbi->extent_lock);
246 	f2fs_bug_on(sbi, list_empty(&en->list));
247 	list_del_init(&en->list);
248 	spin_unlock(&sbi->extent_lock);
249 
250 	__detach_extent_node(sbi, et, en);
251 }
252 
253 static struct extent_tree *__grab_extent_tree(struct inode *inode)
254 {
255 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
256 	struct extent_tree *et;
257 	nid_t ino = inode->i_ino;
258 
259 	mutex_lock(&sbi->extent_tree_lock);
260 	et = radix_tree_lookup(&sbi->extent_tree_root, ino);
261 	if (!et) {
262 		et = f2fs_kmem_cache_alloc(extent_tree_slab, GFP_NOFS);
263 		f2fs_radix_tree_insert(&sbi->extent_tree_root, ino, et);
264 		memset(et, 0, sizeof(struct extent_tree));
265 		et->ino = ino;
266 		et->root = RB_ROOT_CACHED;
267 		et->cached_en = NULL;
268 		rwlock_init(&et->lock);
269 		INIT_LIST_HEAD(&et->list);
270 		atomic_set(&et->node_cnt, 0);
271 		atomic_inc(&sbi->total_ext_tree);
272 	} else {
273 		atomic_dec(&sbi->total_zombie_tree);
274 		list_del_init(&et->list);
275 	}
276 	mutex_unlock(&sbi->extent_tree_lock);
277 
278 	/* never died until evict_inode */
279 	F2FS_I(inode)->extent_tree = et;
280 
281 	return et;
282 }
283 
284 static struct extent_node *__init_extent_tree(struct f2fs_sb_info *sbi,
285 				struct extent_tree *et, struct extent_info *ei)
286 {
287 	struct rb_node **p = &et->root.rb_root.rb_node;
288 	struct extent_node *en;
289 
290 	en = __attach_extent_node(sbi, et, ei, NULL, p, true);
291 	if (!en)
292 		return NULL;
293 
294 	et->largest = en->ei;
295 	et->cached_en = en;
296 	return en;
297 }
298 
299 static unsigned int __free_extent_tree(struct f2fs_sb_info *sbi,
300 					struct extent_tree *et)
301 {
302 	struct rb_node *node, *next;
303 	struct extent_node *en;
304 	unsigned int count = atomic_read(&et->node_cnt);
305 
306 	node = rb_first_cached(&et->root);
307 	while (node) {
308 		next = rb_next(node);
309 		en = rb_entry(node, struct extent_node, rb_node);
310 		__release_extent_node(sbi, et, en);
311 		node = next;
312 	}
313 
314 	return count - atomic_read(&et->node_cnt);
315 }
316 
317 static void __drop_largest_extent(struct extent_tree *et,
318 					pgoff_t fofs, unsigned int len)
319 {
320 	if (fofs < et->largest.fofs + et->largest.len &&
321 			fofs + len > et->largest.fofs) {
322 		et->largest.len = 0;
323 		et->largest_updated = true;
324 	}
325 }
326 
327 /* return true, if inode page is changed */
328 static bool __f2fs_init_extent_tree(struct inode *inode, struct f2fs_extent *i_ext)
329 {
330 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
331 	struct extent_tree *et;
332 	struct extent_node *en;
333 	struct extent_info ei;
334 
335 	if (!f2fs_may_extent_tree(inode)) {
336 		/* drop largest extent */
337 		if (i_ext && i_ext->len) {
338 			i_ext->len = 0;
339 			return true;
340 		}
341 		return false;
342 	}
343 
344 	et = __grab_extent_tree(inode);
345 
346 	if (!i_ext || !i_ext->len)
347 		return false;
348 
349 	get_extent_info(&ei, i_ext);
350 
351 	write_lock(&et->lock);
352 	if (atomic_read(&et->node_cnt))
353 		goto out;
354 
355 	en = __init_extent_tree(sbi, et, &ei);
356 	if (en) {
357 		spin_lock(&sbi->extent_lock);
358 		list_add_tail(&en->list, &sbi->extent_list);
359 		spin_unlock(&sbi->extent_lock);
360 	}
361 out:
362 	write_unlock(&et->lock);
363 	return false;
364 }
365 
366 bool f2fs_init_extent_tree(struct inode *inode, struct f2fs_extent *i_ext)
367 {
368 	bool ret =  __f2fs_init_extent_tree(inode, i_ext);
369 
370 	if (!F2FS_I(inode)->extent_tree)
371 		set_inode_flag(inode, FI_NO_EXTENT);
372 
373 	return ret;
374 }
375 
376 static bool f2fs_lookup_extent_tree(struct inode *inode, pgoff_t pgofs,
377 							struct extent_info *ei)
378 {
379 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
380 	struct extent_tree *et = F2FS_I(inode)->extent_tree;
381 	struct extent_node *en;
382 	bool ret = false;
383 
384 	f2fs_bug_on(sbi, !et);
385 
386 	trace_f2fs_lookup_extent_tree_start(inode, pgofs);
387 
388 	read_lock(&et->lock);
389 
390 	if (et->largest.fofs <= pgofs &&
391 			et->largest.fofs + et->largest.len > pgofs) {
392 		*ei = et->largest;
393 		ret = true;
394 		stat_inc_largest_node_hit(sbi);
395 		goto out;
396 	}
397 
398 	en = (struct extent_node *)f2fs_lookup_rb_tree(&et->root,
399 				(struct rb_entry *)et->cached_en, pgofs);
400 	if (!en)
401 		goto out;
402 
403 	if (en == et->cached_en)
404 		stat_inc_cached_node_hit(sbi);
405 	else
406 		stat_inc_rbtree_node_hit(sbi);
407 
408 	*ei = en->ei;
409 	spin_lock(&sbi->extent_lock);
410 	if (!list_empty(&en->list)) {
411 		list_move_tail(&en->list, &sbi->extent_list);
412 		et->cached_en = en;
413 	}
414 	spin_unlock(&sbi->extent_lock);
415 	ret = true;
416 out:
417 	stat_inc_total_hit(sbi);
418 	read_unlock(&et->lock);
419 
420 	trace_f2fs_lookup_extent_tree_end(inode, pgofs, ei);
421 	return ret;
422 }
423 
424 static struct extent_node *__try_merge_extent_node(struct f2fs_sb_info *sbi,
425 				struct extent_tree *et, struct extent_info *ei,
426 				struct extent_node *prev_ex,
427 				struct extent_node *next_ex)
428 {
429 	struct extent_node *en = NULL;
430 
431 	if (prev_ex && __is_back_mergeable(ei, &prev_ex->ei)) {
432 		prev_ex->ei.len += ei->len;
433 		ei = &prev_ex->ei;
434 		en = prev_ex;
435 	}
436 
437 	if (next_ex && __is_front_mergeable(ei, &next_ex->ei)) {
438 		next_ex->ei.fofs = ei->fofs;
439 		next_ex->ei.blk = ei->blk;
440 		next_ex->ei.len += ei->len;
441 		if (en)
442 			__release_extent_node(sbi, et, prev_ex);
443 
444 		en = next_ex;
445 	}
446 
447 	if (!en)
448 		return NULL;
449 
450 	__try_update_largest_extent(et, en);
451 
452 	spin_lock(&sbi->extent_lock);
453 	if (!list_empty(&en->list)) {
454 		list_move_tail(&en->list, &sbi->extent_list);
455 		et->cached_en = en;
456 	}
457 	spin_unlock(&sbi->extent_lock);
458 	return en;
459 }
460 
461 static struct extent_node *__insert_extent_tree(struct f2fs_sb_info *sbi,
462 				struct extent_tree *et, struct extent_info *ei,
463 				struct rb_node **insert_p,
464 				struct rb_node *insert_parent,
465 				bool leftmost)
466 {
467 	struct rb_node **p;
468 	struct rb_node *parent = NULL;
469 	struct extent_node *en = NULL;
470 
471 	if (insert_p && insert_parent) {
472 		parent = insert_parent;
473 		p = insert_p;
474 		goto do_insert;
475 	}
476 
477 	leftmost = true;
478 
479 	p = f2fs_lookup_rb_tree_for_insert(sbi, &et->root, &parent,
480 						ei->fofs, &leftmost);
481 do_insert:
482 	en = __attach_extent_node(sbi, et, ei, parent, p, leftmost);
483 	if (!en)
484 		return NULL;
485 
486 	__try_update_largest_extent(et, en);
487 
488 	/* update in global extent list */
489 	spin_lock(&sbi->extent_lock);
490 	list_add_tail(&en->list, &sbi->extent_list);
491 	et->cached_en = en;
492 	spin_unlock(&sbi->extent_lock);
493 	return en;
494 }
495 
496 static void f2fs_update_extent_tree_range(struct inode *inode,
497 				pgoff_t fofs, block_t blkaddr, unsigned int len)
498 {
499 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
500 	struct extent_tree *et = F2FS_I(inode)->extent_tree;
501 	struct extent_node *en = NULL, *en1 = NULL;
502 	struct extent_node *prev_en = NULL, *next_en = NULL;
503 	struct extent_info ei, dei, prev;
504 	struct rb_node **insert_p = NULL, *insert_parent = NULL;
505 	unsigned int end = fofs + len;
506 	unsigned int pos = (unsigned int)fofs;
507 	bool updated = false;
508 	bool leftmost = false;
509 
510 	if (!et)
511 		return;
512 
513 	trace_f2fs_update_extent_tree_range(inode, fofs, blkaddr, len);
514 
515 	write_lock(&et->lock);
516 
517 	if (is_inode_flag_set(inode, FI_NO_EXTENT)) {
518 		write_unlock(&et->lock);
519 		return;
520 	}
521 
522 	prev = et->largest;
523 	dei.len = 0;
524 
525 	/*
526 	 * drop largest extent before lookup, in case it's already
527 	 * been shrunk from extent tree
528 	 */
529 	__drop_largest_extent(et, fofs, len);
530 
531 	/* 1. lookup first extent node in range [fofs, fofs + len - 1] */
532 	en = (struct extent_node *)f2fs_lookup_rb_tree_ret(&et->root,
533 					(struct rb_entry *)et->cached_en, fofs,
534 					(struct rb_entry **)&prev_en,
535 					(struct rb_entry **)&next_en,
536 					&insert_p, &insert_parent, false,
537 					&leftmost);
538 	if (!en)
539 		en = next_en;
540 
541 	/* 2. invlidate all extent nodes in range [fofs, fofs + len - 1] */
542 	while (en && en->ei.fofs < end) {
543 		unsigned int org_end;
544 		int parts = 0;	/* # of parts current extent split into */
545 
546 		next_en = en1 = NULL;
547 
548 		dei = en->ei;
549 		org_end = dei.fofs + dei.len;
550 		f2fs_bug_on(sbi, pos >= org_end);
551 
552 		if (pos > dei.fofs &&	pos - dei.fofs >= F2FS_MIN_EXTENT_LEN) {
553 			en->ei.len = pos - en->ei.fofs;
554 			prev_en = en;
555 			parts = 1;
556 		}
557 
558 		if (end < org_end && org_end - end >= F2FS_MIN_EXTENT_LEN) {
559 			if (parts) {
560 				set_extent_info(&ei, end,
561 						end - dei.fofs + dei.blk,
562 						org_end - end);
563 				en1 = __insert_extent_tree(sbi, et, &ei,
564 							NULL, NULL, true);
565 				next_en = en1;
566 			} else {
567 				en->ei.fofs = end;
568 				en->ei.blk += end - dei.fofs;
569 				en->ei.len -= end - dei.fofs;
570 				next_en = en;
571 			}
572 			parts++;
573 		}
574 
575 		if (!next_en) {
576 			struct rb_node *node = rb_next(&en->rb_node);
577 
578 			next_en = rb_entry_safe(node, struct extent_node,
579 						rb_node);
580 		}
581 
582 		if (parts)
583 			__try_update_largest_extent(et, en);
584 		else
585 			__release_extent_node(sbi, et, en);
586 
587 		/*
588 		 * if original extent is split into zero or two parts, extent
589 		 * tree has been altered by deletion or insertion, therefore
590 		 * invalidate pointers regard to tree.
591 		 */
592 		if (parts != 1) {
593 			insert_p = NULL;
594 			insert_parent = NULL;
595 		}
596 		en = next_en;
597 	}
598 
599 	/* 3. update extent in extent cache */
600 	if (blkaddr) {
601 
602 		set_extent_info(&ei, fofs, blkaddr, len);
603 		if (!__try_merge_extent_node(sbi, et, &ei, prev_en, next_en))
604 			__insert_extent_tree(sbi, et, &ei,
605 					insert_p, insert_parent, leftmost);
606 
607 		/* give up extent_cache, if split and small updates happen */
608 		if (dei.len >= 1 &&
609 				prev.len < F2FS_MIN_EXTENT_LEN &&
610 				et->largest.len < F2FS_MIN_EXTENT_LEN) {
611 			et->largest.len = 0;
612 			et->largest_updated = true;
613 			set_inode_flag(inode, FI_NO_EXTENT);
614 		}
615 	}
616 
617 	if (is_inode_flag_set(inode, FI_NO_EXTENT))
618 		__free_extent_tree(sbi, et);
619 
620 	if (et->largest_updated) {
621 		et->largest_updated = false;
622 		updated = true;
623 	}
624 
625 	write_unlock(&et->lock);
626 
627 	if (updated)
628 		f2fs_mark_inode_dirty_sync(inode, true);
629 }
630 
631 unsigned int f2fs_shrink_extent_tree(struct f2fs_sb_info *sbi, int nr_shrink)
632 {
633 	struct extent_tree *et, *next;
634 	struct extent_node *en;
635 	unsigned int node_cnt = 0, tree_cnt = 0;
636 	int remained;
637 
638 	if (!test_opt(sbi, EXTENT_CACHE))
639 		return 0;
640 
641 	if (!atomic_read(&sbi->total_zombie_tree))
642 		goto free_node;
643 
644 	if (!mutex_trylock(&sbi->extent_tree_lock))
645 		goto out;
646 
647 	/* 1. remove unreferenced extent tree */
648 	list_for_each_entry_safe(et, next, &sbi->zombie_list, list) {
649 		if (atomic_read(&et->node_cnt)) {
650 			write_lock(&et->lock);
651 			node_cnt += __free_extent_tree(sbi, et);
652 			write_unlock(&et->lock);
653 		}
654 		f2fs_bug_on(sbi, atomic_read(&et->node_cnt));
655 		list_del_init(&et->list);
656 		radix_tree_delete(&sbi->extent_tree_root, et->ino);
657 		kmem_cache_free(extent_tree_slab, et);
658 		atomic_dec(&sbi->total_ext_tree);
659 		atomic_dec(&sbi->total_zombie_tree);
660 		tree_cnt++;
661 
662 		if (node_cnt + tree_cnt >= nr_shrink)
663 			goto unlock_out;
664 		cond_resched();
665 	}
666 	mutex_unlock(&sbi->extent_tree_lock);
667 
668 free_node:
669 	/* 2. remove LRU extent entries */
670 	if (!mutex_trylock(&sbi->extent_tree_lock))
671 		goto out;
672 
673 	remained = nr_shrink - (node_cnt + tree_cnt);
674 
675 	spin_lock(&sbi->extent_lock);
676 	for (; remained > 0; remained--) {
677 		if (list_empty(&sbi->extent_list))
678 			break;
679 		en = list_first_entry(&sbi->extent_list,
680 					struct extent_node, list);
681 		et = en->et;
682 		if (!write_trylock(&et->lock)) {
683 			/* refresh this extent node's position in extent list */
684 			list_move_tail(&en->list, &sbi->extent_list);
685 			continue;
686 		}
687 
688 		list_del_init(&en->list);
689 		spin_unlock(&sbi->extent_lock);
690 
691 		__detach_extent_node(sbi, et, en);
692 
693 		write_unlock(&et->lock);
694 		node_cnt++;
695 		spin_lock(&sbi->extent_lock);
696 	}
697 	spin_unlock(&sbi->extent_lock);
698 
699 unlock_out:
700 	mutex_unlock(&sbi->extent_tree_lock);
701 out:
702 	trace_f2fs_shrink_extent_tree(sbi, node_cnt, tree_cnt);
703 
704 	return node_cnt + tree_cnt;
705 }
706 
707 unsigned int f2fs_destroy_extent_node(struct inode *inode)
708 {
709 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
710 	struct extent_tree *et = F2FS_I(inode)->extent_tree;
711 	unsigned int node_cnt = 0;
712 
713 	if (!et || !atomic_read(&et->node_cnt))
714 		return 0;
715 
716 	write_lock(&et->lock);
717 	node_cnt = __free_extent_tree(sbi, et);
718 	write_unlock(&et->lock);
719 
720 	return node_cnt;
721 }
722 
723 void f2fs_drop_extent_tree(struct inode *inode)
724 {
725 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
726 	struct extent_tree *et = F2FS_I(inode)->extent_tree;
727 	bool updated = false;
728 
729 	if (!f2fs_may_extent_tree(inode))
730 		return;
731 
732 	set_inode_flag(inode, FI_NO_EXTENT);
733 
734 	write_lock(&et->lock);
735 	__free_extent_tree(sbi, et);
736 	if (et->largest.len) {
737 		et->largest.len = 0;
738 		updated = true;
739 	}
740 	write_unlock(&et->lock);
741 	if (updated)
742 		f2fs_mark_inode_dirty_sync(inode, true);
743 }
744 
745 void f2fs_destroy_extent_tree(struct inode *inode)
746 {
747 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
748 	struct extent_tree *et = F2FS_I(inode)->extent_tree;
749 	unsigned int node_cnt = 0;
750 
751 	if (!et)
752 		return;
753 
754 	if (inode->i_nlink && !is_bad_inode(inode) &&
755 					atomic_read(&et->node_cnt)) {
756 		mutex_lock(&sbi->extent_tree_lock);
757 		list_add_tail(&et->list, &sbi->zombie_list);
758 		atomic_inc(&sbi->total_zombie_tree);
759 		mutex_unlock(&sbi->extent_tree_lock);
760 		return;
761 	}
762 
763 	/* free all extent info belong to this extent tree */
764 	node_cnt = f2fs_destroy_extent_node(inode);
765 
766 	/* delete extent tree entry in radix tree */
767 	mutex_lock(&sbi->extent_tree_lock);
768 	f2fs_bug_on(sbi, atomic_read(&et->node_cnt));
769 	radix_tree_delete(&sbi->extent_tree_root, inode->i_ino);
770 	kmem_cache_free(extent_tree_slab, et);
771 	atomic_dec(&sbi->total_ext_tree);
772 	mutex_unlock(&sbi->extent_tree_lock);
773 
774 	F2FS_I(inode)->extent_tree = NULL;
775 
776 	trace_f2fs_destroy_extent_tree(inode, node_cnt);
777 }
778 
779 bool f2fs_lookup_extent_cache(struct inode *inode, pgoff_t pgofs,
780 					struct extent_info *ei)
781 {
782 	if (!f2fs_may_extent_tree(inode))
783 		return false;
784 
785 	return f2fs_lookup_extent_tree(inode, pgofs, ei);
786 }
787 
788 void f2fs_update_extent_cache(struct dnode_of_data *dn)
789 {
790 	pgoff_t fofs;
791 	block_t blkaddr;
792 
793 	if (!f2fs_may_extent_tree(dn->inode))
794 		return;
795 
796 	if (dn->data_blkaddr == NEW_ADDR)
797 		blkaddr = NULL_ADDR;
798 	else
799 		blkaddr = dn->data_blkaddr;
800 
801 	fofs = f2fs_start_bidx_of_node(ofs_of_node(dn->node_page), dn->inode) +
802 								dn->ofs_in_node;
803 	f2fs_update_extent_tree_range(dn->inode, fofs, blkaddr, 1);
804 }
805 
806 void f2fs_update_extent_cache_range(struct dnode_of_data *dn,
807 				pgoff_t fofs, block_t blkaddr, unsigned int len)
808 
809 {
810 	if (!f2fs_may_extent_tree(dn->inode))
811 		return;
812 
813 	f2fs_update_extent_tree_range(dn->inode, fofs, blkaddr, len);
814 }
815 
816 void f2fs_init_extent_cache_info(struct f2fs_sb_info *sbi)
817 {
818 	INIT_RADIX_TREE(&sbi->extent_tree_root, GFP_NOIO);
819 	mutex_init(&sbi->extent_tree_lock);
820 	INIT_LIST_HEAD(&sbi->extent_list);
821 	spin_lock_init(&sbi->extent_lock);
822 	atomic_set(&sbi->total_ext_tree, 0);
823 	INIT_LIST_HEAD(&sbi->zombie_list);
824 	atomic_set(&sbi->total_zombie_tree, 0);
825 	atomic_set(&sbi->total_ext_node, 0);
826 }
827 
828 int __init f2fs_create_extent_cache(void)
829 {
830 	extent_tree_slab = f2fs_kmem_cache_create("f2fs_extent_tree",
831 			sizeof(struct extent_tree));
832 	if (!extent_tree_slab)
833 		return -ENOMEM;
834 	extent_node_slab = f2fs_kmem_cache_create("f2fs_extent_node",
835 			sizeof(struct extent_node));
836 	if (!extent_node_slab) {
837 		kmem_cache_destroy(extent_tree_slab);
838 		return -ENOMEM;
839 	}
840 	return 0;
841 }
842 
843 void f2fs_destroy_extent_cache(void)
844 {
845 	kmem_cache_destroy(extent_node_slab);
846 	kmem_cache_destroy(extent_tree_slab);
847 }
848