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TOMOYO Linux Cross Reference
Linux/fs/f2fs/extent_cache.c

Version: ~ [ linux-5.10-rc1 ] ~ [ linux-5.9.1 ] ~ [ linux-5.8.16 ] ~ [ linux-5.7.19 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.72 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.152 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.202 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.240 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.240 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.140 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.85 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  1 /*
  2  * f2fs extent cache support
  3  *
  4  * Copyright (c) 2015 Motorola Mobility
  5  * Copyright (c) 2015 Samsung Electronics
  6  * Authors: Jaegeuk Kim <jaegeuk@kernel.org>
  7  *          Chao Yu <chao2.yu@samsung.com>
  8  *
  9  * This program is free software; you can redistribute it and/or modify
 10  * it under the terms of the GNU General Public License version 2 as
 11  * published by the Free Software Foundation.
 12  */
 13 
 14 #include <linux/fs.h>
 15 #include <linux/f2fs_fs.h>
 16 
 17 #include "f2fs.h"
 18 #include "node.h"
 19 #include <trace/events/f2fs.h>
 20 
 21 static struct rb_entry *__lookup_rb_tree_fast(struct rb_entry *cached_re,
 22                                                         unsigned int ofs)
 23 {
 24         if (cached_re) {
 25                 if (cached_re->ofs <= ofs &&
 26                                 cached_re->ofs + cached_re->len > ofs) {
 27                         return cached_re;
 28                 }
 29         }
 30         return NULL;
 31 }
 32 
 33 static struct rb_entry *__lookup_rb_tree_slow(struct rb_root *root,
 34                                                         unsigned int ofs)
 35 {
 36         struct rb_node *node = root->rb_node;
 37         struct rb_entry *re;
 38 
 39         while (node) {
 40                 re = rb_entry(node, struct rb_entry, rb_node);
 41 
 42                 if (ofs < re->ofs)
 43                         node = node->rb_left;
 44                 else if (ofs >= re->ofs + re->len)
 45                         node = node->rb_right;
 46                 else
 47                         return re;
 48         }
 49         return NULL;
 50 }
 51 
 52 struct rb_entry *__lookup_rb_tree(struct rb_root *root,
 53                                 struct rb_entry *cached_re, unsigned int ofs)
 54 {
 55         struct rb_entry *re;
 56 
 57         re = __lookup_rb_tree_fast(cached_re, ofs);
 58         if (!re)
 59                 return __lookup_rb_tree_slow(root, ofs);
 60 
 61         return re;
 62 }
 63 
 64 struct rb_node **__lookup_rb_tree_for_insert(struct f2fs_sb_info *sbi,
 65                                 struct rb_root *root, struct rb_node **parent,
 66                                 unsigned int ofs)
 67 {
 68         struct rb_node **p = &root->rb_node;
 69         struct rb_entry *re;
 70 
 71         while (*p) {
 72                 *parent = *p;
 73                 re = rb_entry(*parent, struct rb_entry, rb_node);
 74 
 75                 if (ofs < re->ofs)
 76                         p = &(*p)->rb_left;
 77                 else if (ofs >= re->ofs + re->len)
 78                         p = &(*p)->rb_right;
 79                 else
 80                         f2fs_bug_on(sbi, 1);
 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 *__lookup_rb_tree_ret(struct rb_root *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)
103 {
104         struct rb_node **pnode = &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))
114                 return NULL;
115 
116         if (re) {
117                 if (re->ofs <= ofs && re->ofs + re->len > ofs)
118                         goto lookup_neighbors;
119         }
120 
121         while (*pnode) {
122                 parent = *pnode;
123                 re = rb_entry(*pnode, struct rb_entry, rb_node);
124 
125                 if (ofs < re->ofs)
126                         pnode = &(*pnode)->rb_left;
127                 else if (ofs >= re->ofs + re->len)
128                         pnode = &(*pnode)->rb_right;
129                 else
130                         goto lookup_neighbors;
131         }
132 
133         *insert_p = pnode;
134         *insert_parent = parent;
135 
136         re = rb_entry(parent, struct rb_entry, rb_node);
137         tmp_node = parent;
138         if (parent && ofs > re->ofs)
139                 tmp_node = rb_next(parent);
140         *next_entry = rb_entry_safe(tmp_node, struct rb_entry, rb_node);
141 
142         tmp_node = parent;
143         if (parent && ofs < re->ofs)
144                 tmp_node = rb_prev(parent);
145         *prev_entry = rb_entry_safe(tmp_node, struct rb_entry, rb_node);
146         return NULL;
147 
148 lookup_neighbors:
149         if (ofs == re->ofs || force) {
150                 /* lookup prev node for merging backward later */
151                 tmp_node = rb_prev(&re->rb_node);
152                 *prev_entry = rb_entry_safe(tmp_node, struct rb_entry, rb_node);
153         }
154         if (ofs == re->ofs + re->len - 1 || force) {
155                 /* lookup next node for merging frontward later */
156                 tmp_node = rb_next(&re->rb_node);
157                 *next_entry = rb_entry_safe(tmp_node, struct rb_entry, rb_node);
158         }
159         return re;
160 }
161 
162 bool __check_rb_tree_consistence(struct f2fs_sb_info *sbi,
163                                                 struct rb_root *root)
164 {
165 #ifdef CONFIG_F2FS_CHECK_FS
166         struct rb_node *cur = rb_first(root), *next;
167         struct rb_entry *cur_re, *next_re;
168 
169         if (!cur)
170                 return true;
171 
172         while (cur) {
173                 next = rb_next(cur);
174                 if (!next)
175                         return true;
176 
177                 cur_re = rb_entry(cur, struct rb_entry, rb_node);
178                 next_re = rb_entry(next, struct rb_entry, rb_node);
179 
180                 if (cur_re->ofs + cur_re->len > next_re->ofs) {
181                         f2fs_msg(sbi->sb, KERN_INFO, "inconsistent rbtree, "
182                                 "cur(%u, %u) next(%u, %u)",
183                                 cur_re->ofs, cur_re->len,
184                                 next_re->ofs, next_re->len);
185                         return false;
186                 }
187 
188                 cur = next;
189         }
190 #endif
191         return true;
192 }
193 
194 static struct kmem_cache *extent_tree_slab;
195 static struct kmem_cache *extent_node_slab;
196 
197 static struct extent_node *__attach_extent_node(struct f2fs_sb_info *sbi,
198                                 struct extent_tree *et, struct extent_info *ei,
199                                 struct rb_node *parent, struct rb_node **p)
200 {
201         struct extent_node *en;
202 
203         en = kmem_cache_alloc(extent_node_slab, GFP_ATOMIC);
204         if (!en)
205                 return NULL;
206 
207         en->ei = *ei;
208         INIT_LIST_HEAD(&en->list);
209         en->et = et;
210 
211         rb_link_node(&en->rb_node, parent, p);
212         rb_insert_color(&en->rb_node, &et->root);
213         atomic_inc(&et->node_cnt);
214         atomic_inc(&sbi->total_ext_node);
215         return en;
216 }
217 
218 static void __detach_extent_node(struct f2fs_sb_info *sbi,
219                                 struct extent_tree *et, struct extent_node *en)
220 {
221         rb_erase(&en->rb_node, &et->root);
222         atomic_dec(&et->node_cnt);
223         atomic_dec(&sbi->total_ext_node);
224 
225         if (et->cached_en == en)
226                 et->cached_en = NULL;
227         kmem_cache_free(extent_node_slab, en);
228 }
229 
230 /*
231  * Flow to release an extent_node:
232  * 1. list_del_init
233  * 2. __detach_extent_node
234  * 3. kmem_cache_free.
235  */
236 static void __release_extent_node(struct f2fs_sb_info *sbi,
237                         struct extent_tree *et, struct extent_node *en)
238 {
239         spin_lock(&sbi->extent_lock);
240         f2fs_bug_on(sbi, list_empty(&en->list));
241         list_del_init(&en->list);
242         spin_unlock(&sbi->extent_lock);
243 
244         __detach_extent_node(sbi, et, en);
245 }
246 
247 static struct extent_tree *__grab_extent_tree(struct inode *inode)
248 {
249         struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
250         struct extent_tree *et;
251         nid_t ino = inode->i_ino;
252 
253         mutex_lock(&sbi->extent_tree_lock);
254         et = radix_tree_lookup(&sbi->extent_tree_root, ino);
255         if (!et) {
256                 et = f2fs_kmem_cache_alloc(extent_tree_slab, GFP_NOFS);
257                 f2fs_radix_tree_insert(&sbi->extent_tree_root, ino, et);
258                 memset(et, 0, sizeof(struct extent_tree));
259                 et->ino = ino;
260                 et->root = RB_ROOT;
261                 et->cached_en = NULL;
262                 rwlock_init(&et->lock);
263                 INIT_LIST_HEAD(&et->list);
264                 atomic_set(&et->node_cnt, 0);
265                 atomic_inc(&sbi->total_ext_tree);
266         } else {
267                 atomic_dec(&sbi->total_zombie_tree);
268                 list_del_init(&et->list);
269         }
270         mutex_unlock(&sbi->extent_tree_lock);
271 
272         /* never died until evict_inode */
273         F2FS_I(inode)->extent_tree = et;
274 
275         return et;
276 }
277 
278 static struct extent_node *__init_extent_tree(struct f2fs_sb_info *sbi,
279                                 struct extent_tree *et, struct extent_info *ei)
280 {
281         struct rb_node **p = &et->root.rb_node;
282         struct extent_node *en;
283 
284         en = __attach_extent_node(sbi, et, ei, NULL, p);
285         if (!en)
286                 return NULL;
287 
288         et->largest = en->ei;
289         et->cached_en = en;
290         return en;
291 }
292 
293 static unsigned int __free_extent_tree(struct f2fs_sb_info *sbi,
294                                         struct extent_tree *et)
295 {
296         struct rb_node *node, *next;
297         struct extent_node *en;
298         unsigned int count = atomic_read(&et->node_cnt);
299 
300         node = rb_first(&et->root);
301         while (node) {
302                 next = rb_next(node);
303                 en = rb_entry(node, struct extent_node, rb_node);
304                 __release_extent_node(sbi, et, en);
305                 node = next;
306         }
307 
308         return count - atomic_read(&et->node_cnt);
309 }
310 
311 static void __drop_largest_extent(struct inode *inode,
312                                         pgoff_t fofs, unsigned int len)
313 {
314         struct extent_info *largest = &F2FS_I(inode)->extent_tree->largest;
315 
316         if (fofs < largest->fofs + largest->len && fofs + len > largest->fofs) {
317                 largest->len = 0;
318                 f2fs_mark_inode_dirty_sync(inode, true);
319         }
320 }
321 
322 /* return true, if inode page is changed */
323 static bool __f2fs_init_extent_tree(struct inode *inode, struct f2fs_extent *i_ext)
324 {
325         struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
326         struct extent_tree *et;
327         struct extent_node *en;
328         struct extent_info ei;
329 
330         if (!f2fs_may_extent_tree(inode)) {
331                 /* drop largest extent */
332                 if (i_ext && i_ext->len) {
333                         i_ext->len = 0;
334                         return true;
335                 }
336                 return false;
337         }
338 
339         et = __grab_extent_tree(inode);
340 
341         if (!i_ext || !i_ext->len)
342                 return false;
343 
344         get_extent_info(&ei, i_ext);
345 
346         write_lock(&et->lock);
347         if (atomic_read(&et->node_cnt))
348                 goto out;
349 
350         en = __init_extent_tree(sbi, et, &ei);
351         if (en) {
352                 spin_lock(&sbi->extent_lock);
353                 list_add_tail(&en->list, &sbi->extent_list);
354                 spin_unlock(&sbi->extent_lock);
355         }
356 out:
357         write_unlock(&et->lock);
358         return false;
359 }
360 
361 bool f2fs_init_extent_tree(struct inode *inode, struct f2fs_extent *i_ext)
362 {
363         bool ret =  __f2fs_init_extent_tree(inode, i_ext);
364 
365         if (!F2FS_I(inode)->extent_tree)
366                 set_inode_flag(inode, FI_NO_EXTENT);
367 
368         return ret;
369 }
370 
371 static bool f2fs_lookup_extent_tree(struct inode *inode, pgoff_t pgofs,
372                                                         struct extent_info *ei)
373 {
374         struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
375         struct extent_tree *et = F2FS_I(inode)->extent_tree;
376         struct extent_node *en;
377         bool ret = false;
378 
379         f2fs_bug_on(sbi, !et);
380 
381         trace_f2fs_lookup_extent_tree_start(inode, pgofs);
382 
383         read_lock(&et->lock);
384 
385         if (et->largest.fofs <= pgofs &&
386                         et->largest.fofs + et->largest.len > pgofs) {
387                 *ei = et->largest;
388                 ret = true;
389                 stat_inc_largest_node_hit(sbi);
390                 goto out;
391         }
392 
393         en = (struct extent_node *)__lookup_rb_tree(&et->root,
394                                 (struct rb_entry *)et->cached_en, pgofs);
395         if (!en)
396                 goto out;
397 
398         if (en == et->cached_en)
399                 stat_inc_cached_node_hit(sbi);
400         else
401                 stat_inc_rbtree_node_hit(sbi);
402 
403         *ei = en->ei;
404         spin_lock(&sbi->extent_lock);
405         if (!list_empty(&en->list)) {
406                 list_move_tail(&en->list, &sbi->extent_list);
407                 et->cached_en = en;
408         }
409         spin_unlock(&sbi->extent_lock);
410         ret = true;
411 out:
412         stat_inc_total_hit(sbi);
413         read_unlock(&et->lock);
414 
415         trace_f2fs_lookup_extent_tree_end(inode, pgofs, ei);
416         return ret;
417 }
418 
419 static struct extent_node *__try_merge_extent_node(struct inode *inode,
420                                 struct extent_tree *et, struct extent_info *ei,
421                                 struct extent_node *prev_ex,
422                                 struct extent_node *next_ex)
423 {
424         struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
425         struct extent_node *en = NULL;
426 
427         if (prev_ex && __is_back_mergeable(ei, &prev_ex->ei)) {
428                 prev_ex->ei.len += ei->len;
429                 ei = &prev_ex->ei;
430                 en = prev_ex;
431         }
432 
433         if (next_ex && __is_front_mergeable(ei, &next_ex->ei)) {
434                 next_ex->ei.fofs = ei->fofs;
435                 next_ex->ei.blk = ei->blk;
436                 next_ex->ei.len += ei->len;
437                 if (en)
438                         __release_extent_node(sbi, et, prev_ex);
439 
440                 en = next_ex;
441         }
442 
443         if (!en)
444                 return NULL;
445 
446         __try_update_largest_extent(inode, et, en);
447 
448         spin_lock(&sbi->extent_lock);
449         if (!list_empty(&en->list)) {
450                 list_move_tail(&en->list, &sbi->extent_list);
451                 et->cached_en = en;
452         }
453         spin_unlock(&sbi->extent_lock);
454         return en;
455 }
456 
457 static struct extent_node *__insert_extent_tree(struct inode *inode,
458                                 struct extent_tree *et, struct extent_info *ei,
459                                 struct rb_node **insert_p,
460                                 struct rb_node *insert_parent)
461 {
462         struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
463         struct rb_node **p = &et->root.rb_node;
464         struct rb_node *parent = NULL;
465         struct extent_node *en = NULL;
466 
467         if (insert_p && insert_parent) {
468                 parent = insert_parent;
469                 p = insert_p;
470                 goto do_insert;
471         }
472 
473         p = __lookup_rb_tree_for_insert(sbi, &et->root, &parent, ei->fofs);
474 do_insert:
475         en = __attach_extent_node(sbi, et, ei, parent, p);
476         if (!en)
477                 return NULL;
478 
479         __try_update_largest_extent(inode, et, en);
480 
481         /* update in global extent list */
482         spin_lock(&sbi->extent_lock);
483         list_add_tail(&en->list, &sbi->extent_list);
484         et->cached_en = en;
485         spin_unlock(&sbi->extent_lock);
486         return en;
487 }
488 
489 static void f2fs_update_extent_tree_range(struct inode *inode,
490                                 pgoff_t fofs, block_t blkaddr, unsigned int len)
491 {
492         struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
493         struct extent_tree *et = F2FS_I(inode)->extent_tree;
494         struct extent_node *en = NULL, *en1 = NULL;
495         struct extent_node *prev_en = NULL, *next_en = NULL;
496         struct extent_info ei, dei, prev;
497         struct rb_node **insert_p = NULL, *insert_parent = NULL;
498         unsigned int end = fofs + len;
499         unsigned int pos = (unsigned int)fofs;
500 
501         if (!et)
502                 return;
503 
504         trace_f2fs_update_extent_tree_range(inode, fofs, blkaddr, len);
505 
506         write_lock(&et->lock);
507 
508         if (is_inode_flag_set(inode, FI_NO_EXTENT)) {
509                 write_unlock(&et->lock);
510                 return;
511         }
512 
513         prev = et->largest;
514         dei.len = 0;
515 
516         /*
517          * drop largest extent before lookup, in case it's already
518          * been shrunk from extent tree
519          */
520         __drop_largest_extent(inode, fofs, len);
521 
522         /* 1. lookup first extent node in range [fofs, fofs + len - 1] */
523         en = (struct extent_node *)__lookup_rb_tree_ret(&et->root,
524                                         (struct rb_entry *)et->cached_en, fofs,
525                                         (struct rb_entry **)&prev_en,
526                                         (struct rb_entry **)&next_en,
527                                         &insert_p, &insert_parent, false);
528         if (!en)
529                 en = next_en;
530 
531         /* 2. invlidate all extent nodes in range [fofs, fofs + len - 1] */
532         while (en && en->ei.fofs < end) {
533                 unsigned int org_end;
534                 int parts = 0;  /* # of parts current extent split into */
535 
536                 next_en = en1 = NULL;
537 
538                 dei = en->ei;
539                 org_end = dei.fofs + dei.len;
540                 f2fs_bug_on(sbi, pos >= org_end);
541 
542                 if (pos > dei.fofs &&   pos - dei.fofs >= F2FS_MIN_EXTENT_LEN) {
543                         en->ei.len = pos - en->ei.fofs;
544                         prev_en = en;
545                         parts = 1;
546                 }
547 
548                 if (end < org_end && org_end - end >= F2FS_MIN_EXTENT_LEN) {
549                         if (parts) {
550                                 set_extent_info(&ei, end,
551                                                 end - dei.fofs + dei.blk,
552                                                 org_end - end);
553                                 en1 = __insert_extent_tree(inode, et, &ei,
554                                                         NULL, NULL);
555                                 next_en = en1;
556                         } else {
557                                 en->ei.fofs = end;
558                                 en->ei.blk += end - dei.fofs;
559                                 en->ei.len -= end - dei.fofs;
560                                 next_en = en;
561                         }
562                         parts++;
563                 }
564 
565                 if (!next_en) {
566                         struct rb_node *node = rb_next(&en->rb_node);
567 
568                         next_en = rb_entry_safe(node, struct extent_node,
569                                                 rb_node);
570                 }
571 
572                 if (parts)
573                         __try_update_largest_extent(inode, et, en);
574                 else
575                         __release_extent_node(sbi, et, en);
576 
577                 /*
578                  * if original extent is split into zero or two parts, extent
579                  * tree has been altered by deletion or insertion, therefore
580                  * invalidate pointers regard to tree.
581                  */
582                 if (parts != 1) {
583                         insert_p = NULL;
584                         insert_parent = NULL;
585                 }
586                 en = next_en;
587         }
588 
589         /* 3. update extent in extent cache */
590         if (blkaddr) {
591 
592                 set_extent_info(&ei, fofs, blkaddr, len);
593                 if (!__try_merge_extent_node(inode, et, &ei, prev_en, next_en))
594                         __insert_extent_tree(inode, et, &ei,
595                                                 insert_p, insert_parent);
596 
597                 /* give up extent_cache, if split and small updates happen */
598                 if (dei.len >= 1 &&
599                                 prev.len < F2FS_MIN_EXTENT_LEN &&
600                                 et->largest.len < F2FS_MIN_EXTENT_LEN) {
601                         __drop_largest_extent(inode, 0, UINT_MAX);
602                         set_inode_flag(inode, FI_NO_EXTENT);
603                 }
604         }
605 
606         if (is_inode_flag_set(inode, FI_NO_EXTENT))
607                 __free_extent_tree(sbi, et);
608 
609         write_unlock(&et->lock);
610 }
611 
612 unsigned int f2fs_shrink_extent_tree(struct f2fs_sb_info *sbi, int nr_shrink)
613 {
614         struct extent_tree *et, *next;
615         struct extent_node *en;
616         unsigned int node_cnt = 0, tree_cnt = 0;
617         int remained;
618 
619         if (!test_opt(sbi, EXTENT_CACHE))
620                 return 0;
621 
622         if (!atomic_read(&sbi->total_zombie_tree))
623                 goto free_node;
624 
625         if (!mutex_trylock(&sbi->extent_tree_lock))
626                 goto out;
627 
628         /* 1. remove unreferenced extent tree */
629         list_for_each_entry_safe(et, next, &sbi->zombie_list, list) {
630                 if (atomic_read(&et->node_cnt)) {
631                         write_lock(&et->lock);
632                         node_cnt += __free_extent_tree(sbi, et);
633                         write_unlock(&et->lock);
634                 }
635                 f2fs_bug_on(sbi, atomic_read(&et->node_cnt));
636                 list_del_init(&et->list);
637                 radix_tree_delete(&sbi->extent_tree_root, et->ino);
638                 kmem_cache_free(extent_tree_slab, et);
639                 atomic_dec(&sbi->total_ext_tree);
640                 atomic_dec(&sbi->total_zombie_tree);
641                 tree_cnt++;
642 
643                 if (node_cnt + tree_cnt >= nr_shrink)
644                         goto unlock_out;
645                 cond_resched();
646         }
647         mutex_unlock(&sbi->extent_tree_lock);
648 
649 free_node:
650         /* 2. remove LRU extent entries */
651         if (!mutex_trylock(&sbi->extent_tree_lock))
652                 goto out;
653 
654         remained = nr_shrink - (node_cnt + tree_cnt);
655 
656         spin_lock(&sbi->extent_lock);
657         for (; remained > 0; remained--) {
658                 if (list_empty(&sbi->extent_list))
659                         break;
660                 en = list_first_entry(&sbi->extent_list,
661                                         struct extent_node, list);
662                 et = en->et;
663                 if (!write_trylock(&et->lock)) {
664                         /* refresh this extent node's position in extent list */
665                         list_move_tail(&en->list, &sbi->extent_list);
666                         continue;
667                 }
668 
669                 list_del_init(&en->list);
670                 spin_unlock(&sbi->extent_lock);
671 
672                 __detach_extent_node(sbi, et, en);
673 
674                 write_unlock(&et->lock);
675                 node_cnt++;
676                 spin_lock(&sbi->extent_lock);
677         }
678         spin_unlock(&sbi->extent_lock);
679 
680 unlock_out:
681         mutex_unlock(&sbi->extent_tree_lock);
682 out:
683         trace_f2fs_shrink_extent_tree(sbi, node_cnt, tree_cnt);
684 
685         return node_cnt + tree_cnt;
686 }
687 
688 unsigned int f2fs_destroy_extent_node(struct inode *inode)
689 {
690         struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
691         struct extent_tree *et = F2FS_I(inode)->extent_tree;
692         unsigned int node_cnt = 0;
693 
694         if (!et || !atomic_read(&et->node_cnt))
695                 return 0;
696 
697         write_lock(&et->lock);
698         node_cnt = __free_extent_tree(sbi, et);
699         write_unlock(&et->lock);
700 
701         return node_cnt;
702 }
703 
704 void f2fs_drop_extent_tree(struct inode *inode)
705 {
706         struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
707         struct extent_tree *et = F2FS_I(inode)->extent_tree;
708 
709         set_inode_flag(inode, FI_NO_EXTENT);
710 
711         write_lock(&et->lock);
712         __free_extent_tree(sbi, et);
713         __drop_largest_extent(inode, 0, UINT_MAX);
714         write_unlock(&et->lock);
715 }
716 
717 void f2fs_destroy_extent_tree(struct inode *inode)
718 {
719         struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
720         struct extent_tree *et = F2FS_I(inode)->extent_tree;
721         unsigned int node_cnt = 0;
722 
723         if (!et)
724                 return;
725 
726         if (inode->i_nlink && !is_bad_inode(inode) &&
727                                         atomic_read(&et->node_cnt)) {
728                 mutex_lock(&sbi->extent_tree_lock);
729                 list_add_tail(&et->list, &sbi->zombie_list);
730                 atomic_inc(&sbi->total_zombie_tree);
731                 mutex_unlock(&sbi->extent_tree_lock);
732                 return;
733         }
734 
735         /* free all extent info belong to this extent tree */
736         node_cnt = f2fs_destroy_extent_node(inode);
737 
738         /* delete extent tree entry in radix tree */
739         mutex_lock(&sbi->extent_tree_lock);
740         f2fs_bug_on(sbi, atomic_read(&et->node_cnt));
741         radix_tree_delete(&sbi->extent_tree_root, inode->i_ino);
742         kmem_cache_free(extent_tree_slab, et);
743         atomic_dec(&sbi->total_ext_tree);
744         mutex_unlock(&sbi->extent_tree_lock);
745 
746         F2FS_I(inode)->extent_tree = NULL;
747 
748         trace_f2fs_destroy_extent_tree(inode, node_cnt);
749 }
750 
751 bool f2fs_lookup_extent_cache(struct inode *inode, pgoff_t pgofs,
752                                         struct extent_info *ei)
753 {
754         if (!f2fs_may_extent_tree(inode))
755                 return false;
756 
757         return f2fs_lookup_extent_tree(inode, pgofs, ei);
758 }
759 
760 void f2fs_update_extent_cache(struct dnode_of_data *dn)
761 {
762         pgoff_t fofs;
763         block_t blkaddr;
764 
765         if (!f2fs_may_extent_tree(dn->inode))
766                 return;
767 
768         if (dn->data_blkaddr == NEW_ADDR)
769                 blkaddr = NULL_ADDR;
770         else
771                 blkaddr = dn->data_blkaddr;
772 
773         fofs = start_bidx_of_node(ofs_of_node(dn->node_page), dn->inode) +
774                                                                 dn->ofs_in_node;
775         f2fs_update_extent_tree_range(dn->inode, fofs, blkaddr, 1);
776 }
777 
778 void f2fs_update_extent_cache_range(struct dnode_of_data *dn,
779                                 pgoff_t fofs, block_t blkaddr, unsigned int len)
780 
781 {
782         if (!f2fs_may_extent_tree(dn->inode))
783                 return;
784 
785         f2fs_update_extent_tree_range(dn->inode, fofs, blkaddr, len);
786 }
787 
788 void init_extent_cache_info(struct f2fs_sb_info *sbi)
789 {
790         INIT_RADIX_TREE(&sbi->extent_tree_root, GFP_NOIO);
791         mutex_init(&sbi->extent_tree_lock);
792         INIT_LIST_HEAD(&sbi->extent_list);
793         spin_lock_init(&sbi->extent_lock);
794         atomic_set(&sbi->total_ext_tree, 0);
795         INIT_LIST_HEAD(&sbi->zombie_list);
796         atomic_set(&sbi->total_zombie_tree, 0);
797         atomic_set(&sbi->total_ext_node, 0);
798 }
799 
800 int __init create_extent_cache(void)
801 {
802         extent_tree_slab = f2fs_kmem_cache_create("f2fs_extent_tree",
803                         sizeof(struct extent_tree));
804         if (!extent_tree_slab)
805                 return -ENOMEM;
806         extent_node_slab = f2fs_kmem_cache_create("f2fs_extent_node",
807                         sizeof(struct extent_node));
808         if (!extent_node_slab) {
809                 kmem_cache_destroy(extent_tree_slab);
810                 return -ENOMEM;
811         }
812         return 0;
813 }
814 
815 void destroy_extent_cache(void)
816 {
817         kmem_cache_destroy(extent_node_slab);
818         kmem_cache_destroy(extent_tree_slab);
819 }
820 

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