fs/f2fs/extent_cache.c

   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 }