xref: /openbmc/linux/fs/f2fs/extent_cache.c (revision dd5b2498)
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_msg(sbi->sb, KERN_INFO, "inconsistent rbtree, "
188 				"cur(%u, %u) next(%u, %u)",
189 				cur_re->ofs, cur_re->len,
190 				next_re->ofs, next_re->len);
191 			return false;
192 		}
193 
194 		cur = next;
195 	}
196 #endif
197 	return true;
198 }
199 
200 static struct kmem_cache *extent_tree_slab;
201 static struct kmem_cache *extent_node_slab;
202 
203 static struct extent_node *__attach_extent_node(struct f2fs_sb_info *sbi,
204 				struct extent_tree *et, struct extent_info *ei,
205 				struct rb_node *parent, struct rb_node **p,
206 				bool leftmost)
207 {
208 	struct extent_node *en;
209 
210 	en = kmem_cache_alloc(extent_node_slab, GFP_ATOMIC);
211 	if (!en)
212 		return NULL;
213 
214 	en->ei = *ei;
215 	INIT_LIST_HEAD(&en->list);
216 	en->et = et;
217 
218 	rb_link_node(&en->rb_node, parent, p);
219 	rb_insert_color_cached(&en->rb_node, &et->root, leftmost);
220 	atomic_inc(&et->node_cnt);
221 	atomic_inc(&sbi->total_ext_node);
222 	return en;
223 }
224 
225 static void __detach_extent_node(struct f2fs_sb_info *sbi,
226 				struct extent_tree *et, struct extent_node *en)
227 {
228 	rb_erase_cached(&en->rb_node, &et->root);
229 	atomic_dec(&et->node_cnt);
230 	atomic_dec(&sbi->total_ext_node);
231 
232 	if (et->cached_en == en)
233 		et->cached_en = NULL;
234 	kmem_cache_free(extent_node_slab, en);
235 }
236 
237 /*
238  * Flow to release an extent_node:
239  * 1. list_del_init
240  * 2. __detach_extent_node
241  * 3. kmem_cache_free.
242  */
243 static void __release_extent_node(struct f2fs_sb_info *sbi,
244 			struct extent_tree *et, struct extent_node *en)
245 {
246 	spin_lock(&sbi->extent_lock);
247 	f2fs_bug_on(sbi, list_empty(&en->list));
248 	list_del_init(&en->list);
249 	spin_unlock(&sbi->extent_lock);
250 
251 	__detach_extent_node(sbi, et, en);
252 }
253 
254 static struct extent_tree *__grab_extent_tree(struct inode *inode)
255 {
256 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
257 	struct extent_tree *et;
258 	nid_t ino = inode->i_ino;
259 
260 	mutex_lock(&sbi->extent_tree_lock);
261 	et = radix_tree_lookup(&sbi->extent_tree_root, ino);
262 	if (!et) {
263 		et = f2fs_kmem_cache_alloc(extent_tree_slab, GFP_NOFS);
264 		f2fs_radix_tree_insert(&sbi->extent_tree_root, ino, et);
265 		memset(et, 0, sizeof(struct extent_tree));
266 		et->ino = ino;
267 		et->root = RB_ROOT_CACHED;
268 		et->cached_en = NULL;
269 		rwlock_init(&et->lock);
270 		INIT_LIST_HEAD(&et->list);
271 		atomic_set(&et->node_cnt, 0);
272 		atomic_inc(&sbi->total_ext_tree);
273 	} else {
274 		atomic_dec(&sbi->total_zombie_tree);
275 		list_del_init(&et->list);
276 	}
277 	mutex_unlock(&sbi->extent_tree_lock);
278 
279 	/* never died until evict_inode */
280 	F2FS_I(inode)->extent_tree = et;
281 
282 	return et;
283 }
284 
285 static struct extent_node *__init_extent_tree(struct f2fs_sb_info *sbi,
286 				struct extent_tree *et, struct extent_info *ei)
287 {
288 	struct rb_node **p = &et->root.rb_root.rb_node;
289 	struct extent_node *en;
290 
291 	en = __attach_extent_node(sbi, et, ei, NULL, p, true);
292 	if (!en)
293 		return NULL;
294 
295 	et->largest = en->ei;
296 	et->cached_en = en;
297 	return en;
298 }
299 
300 static unsigned int __free_extent_tree(struct f2fs_sb_info *sbi,
301 					struct extent_tree *et)
302 {
303 	struct rb_node *node, *next;
304 	struct extent_node *en;
305 	unsigned int count = atomic_read(&et->node_cnt);
306 
307 	node = rb_first_cached(&et->root);
308 	while (node) {
309 		next = rb_next(node);
310 		en = rb_entry(node, struct extent_node, rb_node);
311 		__release_extent_node(sbi, et, en);
312 		node = next;
313 	}
314 
315 	return count - atomic_read(&et->node_cnt);
316 }
317 
318 static void __drop_largest_extent(struct extent_tree *et,
319 					pgoff_t fofs, unsigned int len)
320 {
321 	if (fofs < et->largest.fofs + et->largest.len &&
322 			fofs + len > et->largest.fofs) {
323 		et->largest.len = 0;
324 		et->largest_updated = true;
325 	}
326 }
327 
328 /* return true, if inode page is changed */
329 static bool __f2fs_init_extent_tree(struct inode *inode, struct f2fs_extent *i_ext)
330 {
331 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
332 	struct extent_tree *et;
333 	struct extent_node *en;
334 	struct extent_info ei;
335 
336 	if (!f2fs_may_extent_tree(inode)) {
337 		/* drop largest extent */
338 		if (i_ext && i_ext->len) {
339 			i_ext->len = 0;
340 			return true;
341 		}
342 		return false;
343 	}
344 
345 	et = __grab_extent_tree(inode);
346 
347 	if (!i_ext || !i_ext->len)
348 		return false;
349 
350 	get_extent_info(&ei, i_ext);
351 
352 	write_lock(&et->lock);
353 	if (atomic_read(&et->node_cnt))
354 		goto out;
355 
356 	en = __init_extent_tree(sbi, et, &ei);
357 	if (en) {
358 		spin_lock(&sbi->extent_lock);
359 		list_add_tail(&en->list, &sbi->extent_list);
360 		spin_unlock(&sbi->extent_lock);
361 	}
362 out:
363 	write_unlock(&et->lock);
364 	return false;
365 }
366 
367 bool f2fs_init_extent_tree(struct inode *inode, struct f2fs_extent *i_ext)
368 {
369 	bool ret =  __f2fs_init_extent_tree(inode, i_ext);
370 
371 	if (!F2FS_I(inode)->extent_tree)
372 		set_inode_flag(inode, FI_NO_EXTENT);
373 
374 	return ret;
375 }
376 
377 static bool f2fs_lookup_extent_tree(struct inode *inode, pgoff_t pgofs,
378 							struct extent_info *ei)
379 {
380 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
381 	struct extent_tree *et = F2FS_I(inode)->extent_tree;
382 	struct extent_node *en;
383 	bool ret = false;
384 
385 	f2fs_bug_on(sbi, !et);
386 
387 	trace_f2fs_lookup_extent_tree_start(inode, pgofs);
388 
389 	read_lock(&et->lock);
390 
391 	if (et->largest.fofs <= pgofs &&
392 			et->largest.fofs + et->largest.len > pgofs) {
393 		*ei = et->largest;
394 		ret = true;
395 		stat_inc_largest_node_hit(sbi);
396 		goto out;
397 	}
398 
399 	en = (struct extent_node *)f2fs_lookup_rb_tree(&et->root,
400 				(struct rb_entry *)et->cached_en, pgofs);
401 	if (!en)
402 		goto out;
403 
404 	if (en == et->cached_en)
405 		stat_inc_cached_node_hit(sbi);
406 	else
407 		stat_inc_rbtree_node_hit(sbi);
408 
409 	*ei = en->ei;
410 	spin_lock(&sbi->extent_lock);
411 	if (!list_empty(&en->list)) {
412 		list_move_tail(&en->list, &sbi->extent_list);
413 		et->cached_en = en;
414 	}
415 	spin_unlock(&sbi->extent_lock);
416 	ret = true;
417 out:
418 	stat_inc_total_hit(sbi);
419 	read_unlock(&et->lock);
420 
421 	trace_f2fs_lookup_extent_tree_end(inode, pgofs, ei);
422 	return ret;
423 }
424 
425 static struct extent_node *__try_merge_extent_node(struct f2fs_sb_info *sbi,
426 				struct extent_tree *et, struct extent_info *ei,
427 				struct extent_node *prev_ex,
428 				struct extent_node *next_ex)
429 {
430 	struct extent_node *en = NULL;
431 
432 	if (prev_ex && __is_back_mergeable(ei, &prev_ex->ei)) {
433 		prev_ex->ei.len += ei->len;
434 		ei = &prev_ex->ei;
435 		en = prev_ex;
436 	}
437 
438 	if (next_ex && __is_front_mergeable(ei, &next_ex->ei)) {
439 		next_ex->ei.fofs = ei->fofs;
440 		next_ex->ei.blk = ei->blk;
441 		next_ex->ei.len += ei->len;
442 		if (en)
443 			__release_extent_node(sbi, et, prev_ex);
444 
445 		en = next_ex;
446 	}
447 
448 	if (!en)
449 		return NULL;
450 
451 	__try_update_largest_extent(et, en);
452 
453 	spin_lock(&sbi->extent_lock);
454 	if (!list_empty(&en->list)) {
455 		list_move_tail(&en->list, &sbi->extent_list);
456 		et->cached_en = en;
457 	}
458 	spin_unlock(&sbi->extent_lock);
459 	return en;
460 }
461 
462 static struct extent_node *__insert_extent_tree(struct f2fs_sb_info *sbi,
463 				struct extent_tree *et, struct extent_info *ei,
464 				struct rb_node **insert_p,
465 				struct rb_node *insert_parent,
466 				bool leftmost)
467 {
468 	struct rb_node **p;
469 	struct rb_node *parent = NULL;
470 	struct extent_node *en = NULL;
471 
472 	if (insert_p && insert_parent) {
473 		parent = insert_parent;
474 		p = insert_p;
475 		goto do_insert;
476 	}
477 
478 	leftmost = true;
479 
480 	p = f2fs_lookup_rb_tree_for_insert(sbi, &et->root, &parent,
481 						ei->fofs, &leftmost);
482 do_insert:
483 	en = __attach_extent_node(sbi, et, ei, parent, p, leftmost);
484 	if (!en)
485 		return NULL;
486 
487 	__try_update_largest_extent(et, en);
488 
489 	/* update in global extent list */
490 	spin_lock(&sbi->extent_lock);
491 	list_add_tail(&en->list, &sbi->extent_list);
492 	et->cached_en = en;
493 	spin_unlock(&sbi->extent_lock);
494 	return en;
495 }
496 
497 static void f2fs_update_extent_tree_range(struct inode *inode,
498 				pgoff_t fofs, block_t blkaddr, unsigned int len)
499 {
500 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
501 	struct extent_tree *et = F2FS_I(inode)->extent_tree;
502 	struct extent_node *en = NULL, *en1 = NULL;
503 	struct extent_node *prev_en = NULL, *next_en = NULL;
504 	struct extent_info ei, dei, prev;
505 	struct rb_node **insert_p = NULL, *insert_parent = NULL;
506 	unsigned int end = fofs + len;
507 	unsigned int pos = (unsigned int)fofs;
508 	bool updated = false;
509 	bool leftmost = false;
510 
511 	if (!et)
512 		return;
513 
514 	trace_f2fs_update_extent_tree_range(inode, fofs, blkaddr, len);
515 
516 	write_lock(&et->lock);
517 
518 	if (is_inode_flag_set(inode, FI_NO_EXTENT)) {
519 		write_unlock(&et->lock);
520 		return;
521 	}
522 
523 	prev = et->largest;
524 	dei.len = 0;
525 
526 	/*
527 	 * drop largest extent before lookup, in case it's already
528 	 * been shrunk from extent tree
529 	 */
530 	__drop_largest_extent(et, fofs, len);
531 
532 	/* 1. lookup first extent node in range [fofs, fofs + len - 1] */
533 	en = (struct extent_node *)f2fs_lookup_rb_tree_ret(&et->root,
534 					(struct rb_entry *)et->cached_en, fofs,
535 					(struct rb_entry **)&prev_en,
536 					(struct rb_entry **)&next_en,
537 					&insert_p, &insert_parent, false,
538 					&leftmost);
539 	if (!en)
540 		en = next_en;
541 
542 	/* 2. invlidate all extent nodes in range [fofs, fofs + len - 1] */
543 	while (en && en->ei.fofs < end) {
544 		unsigned int org_end;
545 		int parts = 0;	/* # of parts current extent split into */
546 
547 		next_en = en1 = NULL;
548 
549 		dei = en->ei;
550 		org_end = dei.fofs + dei.len;
551 		f2fs_bug_on(sbi, pos >= org_end);
552 
553 		if (pos > dei.fofs &&	pos - dei.fofs >= F2FS_MIN_EXTENT_LEN) {
554 			en->ei.len = pos - en->ei.fofs;
555 			prev_en = en;
556 			parts = 1;
557 		}
558 
559 		if (end < org_end && org_end - end >= F2FS_MIN_EXTENT_LEN) {
560 			if (parts) {
561 				set_extent_info(&ei, end,
562 						end - dei.fofs + dei.blk,
563 						org_end - end);
564 				en1 = __insert_extent_tree(sbi, et, &ei,
565 							NULL, NULL, true);
566 				next_en = en1;
567 			} else {
568 				en->ei.fofs = end;
569 				en->ei.blk += end - dei.fofs;
570 				en->ei.len -= end - dei.fofs;
571 				next_en = en;
572 			}
573 			parts++;
574 		}
575 
576 		if (!next_en) {
577 			struct rb_node *node = rb_next(&en->rb_node);
578 
579 			next_en = rb_entry_safe(node, struct extent_node,
580 						rb_node);
581 		}
582 
583 		if (parts)
584 			__try_update_largest_extent(et, en);
585 		else
586 			__release_extent_node(sbi, et, en);
587 
588 		/*
589 		 * if original extent is split into zero or two parts, extent
590 		 * tree has been altered by deletion or insertion, therefore
591 		 * invalidate pointers regard to tree.
592 		 */
593 		if (parts != 1) {
594 			insert_p = NULL;
595 			insert_parent = NULL;
596 		}
597 		en = next_en;
598 	}
599 
600 	/* 3. update extent in extent cache */
601 	if (blkaddr) {
602 
603 		set_extent_info(&ei, fofs, blkaddr, len);
604 		if (!__try_merge_extent_node(sbi, et, &ei, prev_en, next_en))
605 			__insert_extent_tree(sbi, et, &ei,
606 					insert_p, insert_parent, leftmost);
607 
608 		/* give up extent_cache, if split and small updates happen */
609 		if (dei.len >= 1 &&
610 				prev.len < F2FS_MIN_EXTENT_LEN &&
611 				et->largest.len < F2FS_MIN_EXTENT_LEN) {
612 			et->largest.len = 0;
613 			et->largest_updated = true;
614 			set_inode_flag(inode, FI_NO_EXTENT);
615 		}
616 	}
617 
618 	if (is_inode_flag_set(inode, FI_NO_EXTENT))
619 		__free_extent_tree(sbi, et);
620 
621 	if (et->largest_updated) {
622 		et->largest_updated = false;
623 		updated = true;
624 	}
625 
626 	write_unlock(&et->lock);
627 
628 	if (updated)
629 		f2fs_mark_inode_dirty_sync(inode, true);
630 }
631 
632 unsigned int f2fs_shrink_extent_tree(struct f2fs_sb_info *sbi, int nr_shrink)
633 {
634 	struct extent_tree *et, *next;
635 	struct extent_node *en;
636 	unsigned int node_cnt = 0, tree_cnt = 0;
637 	int remained;
638 
639 	if (!test_opt(sbi, EXTENT_CACHE))
640 		return 0;
641 
642 	if (!atomic_read(&sbi->total_zombie_tree))
643 		goto free_node;
644 
645 	if (!mutex_trylock(&sbi->extent_tree_lock))
646 		goto out;
647 
648 	/* 1. remove unreferenced extent tree */
649 	list_for_each_entry_safe(et, next, &sbi->zombie_list, list) {
650 		if (atomic_read(&et->node_cnt)) {
651 			write_lock(&et->lock);
652 			node_cnt += __free_extent_tree(sbi, et);
653 			write_unlock(&et->lock);
654 		}
655 		f2fs_bug_on(sbi, atomic_read(&et->node_cnt));
656 		list_del_init(&et->list);
657 		radix_tree_delete(&sbi->extent_tree_root, et->ino);
658 		kmem_cache_free(extent_tree_slab, et);
659 		atomic_dec(&sbi->total_ext_tree);
660 		atomic_dec(&sbi->total_zombie_tree);
661 		tree_cnt++;
662 
663 		if (node_cnt + tree_cnt >= nr_shrink)
664 			goto unlock_out;
665 		cond_resched();
666 	}
667 	mutex_unlock(&sbi->extent_tree_lock);
668 
669 free_node:
670 	/* 2. remove LRU extent entries */
671 	if (!mutex_trylock(&sbi->extent_tree_lock))
672 		goto out;
673 
674 	remained = nr_shrink - (node_cnt + tree_cnt);
675 
676 	spin_lock(&sbi->extent_lock);
677 	for (; remained > 0; remained--) {
678 		if (list_empty(&sbi->extent_list))
679 			break;
680 		en = list_first_entry(&sbi->extent_list,
681 					struct extent_node, list);
682 		et = en->et;
683 		if (!write_trylock(&et->lock)) {
684 			/* refresh this extent node's position in extent list */
685 			list_move_tail(&en->list, &sbi->extent_list);
686 			continue;
687 		}
688 
689 		list_del_init(&en->list);
690 		spin_unlock(&sbi->extent_lock);
691 
692 		__detach_extent_node(sbi, et, en);
693 
694 		write_unlock(&et->lock);
695 		node_cnt++;
696 		spin_lock(&sbi->extent_lock);
697 	}
698 	spin_unlock(&sbi->extent_lock);
699 
700 unlock_out:
701 	mutex_unlock(&sbi->extent_tree_lock);
702 out:
703 	trace_f2fs_shrink_extent_tree(sbi, node_cnt, tree_cnt);
704 
705 	return node_cnt + tree_cnt;
706 }
707 
708 unsigned int f2fs_destroy_extent_node(struct inode *inode)
709 {
710 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
711 	struct extent_tree *et = F2FS_I(inode)->extent_tree;
712 	unsigned int node_cnt = 0;
713 
714 	if (!et || !atomic_read(&et->node_cnt))
715 		return 0;
716 
717 	write_lock(&et->lock);
718 	node_cnt = __free_extent_tree(sbi, et);
719 	write_unlock(&et->lock);
720 
721 	return node_cnt;
722 }
723 
724 void f2fs_drop_extent_tree(struct inode *inode)
725 {
726 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
727 	struct extent_tree *et = F2FS_I(inode)->extent_tree;
728 	bool updated = false;
729 
730 	if (!f2fs_may_extent_tree(inode))
731 		return;
732 
733 	set_inode_flag(inode, FI_NO_EXTENT);
734 
735 	write_lock(&et->lock);
736 	__free_extent_tree(sbi, et);
737 	if (et->largest.len) {
738 		et->largest.len = 0;
739 		updated = true;
740 	}
741 	write_unlock(&et->lock);
742 	if (updated)
743 		f2fs_mark_inode_dirty_sync(inode, true);
744 }
745 
746 void f2fs_destroy_extent_tree(struct inode *inode)
747 {
748 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
749 	struct extent_tree *et = F2FS_I(inode)->extent_tree;
750 	unsigned int node_cnt = 0;
751 
752 	if (!et)
753 		return;
754 
755 	if (inode->i_nlink && !is_bad_inode(inode) &&
756 					atomic_read(&et->node_cnt)) {
757 		mutex_lock(&sbi->extent_tree_lock);
758 		list_add_tail(&et->list, &sbi->zombie_list);
759 		atomic_inc(&sbi->total_zombie_tree);
760 		mutex_unlock(&sbi->extent_tree_lock);
761 		return;
762 	}
763 
764 	/* free all extent info belong to this extent tree */
765 	node_cnt = f2fs_destroy_extent_node(inode);
766 
767 	/* delete extent tree entry in radix tree */
768 	mutex_lock(&sbi->extent_tree_lock);
769 	f2fs_bug_on(sbi, atomic_read(&et->node_cnt));
770 	radix_tree_delete(&sbi->extent_tree_root, inode->i_ino);
771 	kmem_cache_free(extent_tree_slab, et);
772 	atomic_dec(&sbi->total_ext_tree);
773 	mutex_unlock(&sbi->extent_tree_lock);
774 
775 	F2FS_I(inode)->extent_tree = NULL;
776 
777 	trace_f2fs_destroy_extent_tree(inode, node_cnt);
778 }
779 
780 bool f2fs_lookup_extent_cache(struct inode *inode, pgoff_t pgofs,
781 					struct extent_info *ei)
782 {
783 	if (!f2fs_may_extent_tree(inode))
784 		return false;
785 
786 	return f2fs_lookup_extent_tree(inode, pgofs, ei);
787 }
788 
789 void f2fs_update_extent_cache(struct dnode_of_data *dn)
790 {
791 	pgoff_t fofs;
792 	block_t blkaddr;
793 
794 	if (!f2fs_may_extent_tree(dn->inode))
795 		return;
796 
797 	if (dn->data_blkaddr == NEW_ADDR)
798 		blkaddr = NULL_ADDR;
799 	else
800 		blkaddr = dn->data_blkaddr;
801 
802 	fofs = f2fs_start_bidx_of_node(ofs_of_node(dn->node_page), dn->inode) +
803 								dn->ofs_in_node;
804 	f2fs_update_extent_tree_range(dn->inode, fofs, blkaddr, 1);
805 }
806 
807 void f2fs_update_extent_cache_range(struct dnode_of_data *dn,
808 				pgoff_t fofs, block_t blkaddr, unsigned int len)
809 
810 {
811 	if (!f2fs_may_extent_tree(dn->inode))
812 		return;
813 
814 	f2fs_update_extent_tree_range(dn->inode, fofs, blkaddr, len);
815 }
816 
817 void f2fs_init_extent_cache_info(struct f2fs_sb_info *sbi)
818 {
819 	INIT_RADIX_TREE(&sbi->extent_tree_root, GFP_NOIO);
820 	mutex_init(&sbi->extent_tree_lock);
821 	INIT_LIST_HEAD(&sbi->extent_list);
822 	spin_lock_init(&sbi->extent_lock);
823 	atomic_set(&sbi->total_ext_tree, 0);
824 	INIT_LIST_HEAD(&sbi->zombie_list);
825 	atomic_set(&sbi->total_zombie_tree, 0);
826 	atomic_set(&sbi->total_ext_node, 0);
827 }
828 
829 int __init f2fs_create_extent_cache(void)
830 {
831 	extent_tree_slab = f2fs_kmem_cache_create("f2fs_extent_tree",
832 			sizeof(struct extent_tree));
833 	if (!extent_tree_slab)
834 		return -ENOMEM;
835 	extent_node_slab = f2fs_kmem_cache_create("f2fs_extent_node",
836 			sizeof(struct extent_node));
837 	if (!extent_node_slab) {
838 		kmem_cache_destroy(extent_tree_slab);
839 		return -ENOMEM;
840 	}
841 	return 0;
842 }
843 
844 void f2fs_destroy_extent_cache(void)
845 {
846 	kmem_cache_destroy(extent_node_slab);
847 	kmem_cache_destroy(extent_tree_slab);
848 }
849