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_ext(struct f2fs_sb_info *sbi,
  62                                         struct rb_root_cached *root,
  63                                         struct rb_node **parent,
  64                                         unsigned long long key, 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 (key < re->key) {
  74                         p = &(*p)->rb_left;
  75                 } else {
  76                         p = &(*p)->rb_right;
  77                         *leftmost = false;
  78                 }
  79         }
  80
  81         return p;
  82 }
  83
  84 struct rb_node **f2fs_lookup_rb_tree_for_insert(struct f2fs_sb_info *sbi,
  85                                 struct rb_root_cached *root,
  86                                 struct rb_node **parent,
  87                                 unsigned int ofs, bool *leftmost)
  88 {
  89         struct rb_node **p = &root->rb_root.rb_node;
  90         struct rb_entry *re;
  91
  92         while (*p) {
  93                 *parent = *p;
  94                 re = rb_entry(*parent, struct rb_entry, rb_node);
  95
  96                 if (ofs < re->ofs) {
  97                         p = &(*p)->rb_left;
  98                 } else if (ofs >= re->ofs + re->len) {
  99                         p = &(*p)->rb_right;
 100                         *leftmost = false;
 101                 } else {
 102                         f2fs_bug_on(sbi, 1);
 103                 }
 104         }
 105
 106         return p;
 107 }
 108
 109 /*
 110  * lookup rb entry in position of @ofs in rb-tree,
 111  * if hit, return the entry, otherwise, return NULL
 112  * @prev_ex: extent before ofs
 113  * @next_ex: extent after ofs
 114  * @insert_p: insert point for new extent at ofs
 115  * in order to simpfy the insertion after.
 116  * tree must stay unchanged between lookup and insertion.
 117  */
 118 struct rb_entry *f2fs_lookup_rb_tree_ret(struct rb_root_cached *root,
 119                                 struct rb_entry *cached_re,
 120                                 unsigned int ofs,
 121                                 struct rb_entry **prev_entry,
 122                                 struct rb_entry **next_entry,
 123                                 struct rb_node ***insert_p,
 124                                 struct rb_node **insert_parent,
 125                                 bool force, bool *leftmost)
 126 {
 127         struct rb_node **pnode = &root->rb_root.rb_node;
 128         struct rb_node *parent = NULL, *tmp_node;
 129         struct rb_entry *re = cached_re;
 130
 131         *insert_p = NULL;
 132         *insert_parent = NULL;
 133         *prev_entry = NULL;
 134         *next_entry = NULL;
 135
 136         if (RB_EMPTY_ROOT(&root->rb_root))
 137                 return NULL;
 138
 139         if (re) {
 140                 if (re->ofs <= ofs && re->ofs + re->len > ofs)
 141                         goto lookup_neighbors;
 142         }
 143
 144         if (leftmost)
 145                 *leftmost = true;
 146
 147         while (*pnode) {
 148                 parent = *pnode;
 149                 re = rb_entry(*pnode, struct rb_entry, rb_node);
 150
 151                 if (ofs < re->ofs) {
 152                         pnode = &(*pnode)->rb_left;
 153                 } else if (ofs >= re->ofs + re->len) {
 154                         pnode = &(*pnode)->rb_right;
 155                         if (leftmost)
 156                                 *leftmost = false;
 157                 } else {
 158                         goto lookup_neighbors;
 159                 }
 160         }
 161
 162         *insert_p = pnode;
 163         *insert_parent = parent;
 164
 165         re = rb_entry(parent, struct rb_entry, rb_node);
 166         tmp_node = parent;
 167         if (parent && ofs > re->ofs)
 168                 tmp_node = rb_next(parent);
 169         *next_entry = rb_entry_safe(tmp_node, struct rb_entry, rb_node);
 170
 171         tmp_node = parent;
 172         if (parent && ofs < re->ofs)
 173                 tmp_node = rb_prev(parent);
 174         *prev_entry = rb_entry_safe(tmp_node, struct rb_entry, rb_node);
 175         return NULL;
 176
 177 lookup_neighbors:
 178         if (ofs == re->ofs || force) {
 179                 /* lookup prev node for merging backward later */
 180                 tmp_node = rb_prev(&re->rb_node);
 181                 *prev_entry = rb_entry_safe(tmp_node, struct rb_entry, rb_node);
 182         }
 183         if (ofs == re->ofs + re->len - 1 || force) {
 184                 /* lookup next node for merging frontward later */
 185                 tmp_node = rb_next(&re->rb_node);
 186                 *next_entry = rb_entry_safe(tmp_node, struct rb_entry, rb_node);
 187         }
 188         return re;
 189 }
 190
 191 bool f2fs_check_rb_tree_consistence(struct f2fs_sb_info *sbi,
 192                                 struct rb_root_cached *root, bool check_key)
 193 {
 194 #ifdef CONFIG_F2FS_CHECK_FS
 195         struct rb_node *cur = rb_first_cached(root), *next;
 196         struct rb_entry *cur_re, *next_re;
 197
 198         if (!cur)
 199                 return true;
 200
 201         while (cur) {
 202                 next = rb_next(cur);
 203                 if (!next)
 204                         return true;
 205
 206                 cur_re = rb_entry(cur, struct rb_entry, rb_node);
 207                 next_re = rb_entry(next, struct rb_entry, rb_node);
 208
 209                 if (check_key) {
 210                         if (cur_re->key > next_re->key) {
 211                                 f2fs_info(sbi, "inconsistent rbtree, "
 212                                         "cur(%llu) next(%llu)",
 213                                         cur_re->key, next_re->key);
 214                                 return false;
 215                         }
 216                         goto next;
 217                 }
 218
 219                 if (cur_re->ofs + cur_re->len > next_re->ofs) {
 220                         f2fs_info(sbi, "inconsistent rbtree, cur(%u, %u) next(%u, %u)",
 221                                   cur_re->ofs, cur_re->len,
 222                                   next_re->ofs, next_re->len);
 223                         return false;
 224                 }
 225 next:
 226                 cur = next;
 227         }
 228 #endif
 229         return true;
 230 }
 231
 232 static struct kmem_cache *extent_tree_slab;
 233 static struct kmem_cache *extent_node_slab;
 234
 235 static struct extent_node *__attach_extent_node(struct f2fs_sb_info *sbi,
 236                                 struct extent_tree *et, struct extent_info *ei,
 237                                 struct rb_node *parent, struct rb_node **p,
 238                                 bool leftmost)
 239 {
 240         struct extent_node *en;
 241
 242         en = kmem_cache_alloc(extent_node_slab, GFP_ATOMIC);
 243         if (!en)
 244                 return NULL;
 245
 246         en->ei = *ei;
 247         INIT_LIST_HEAD(&en->list);
 248         en->et = et;
 249
 250         rb_link_node(&en->rb_node, parent, p);
 251         rb_insert_color_cached(&en->rb_node, &et->root, leftmost);
 252         atomic_inc(&et->node_cnt);
 253         atomic_inc(&sbi->total_ext_node);
 254         return en;
 255 }
 256
 257 static void __detach_extent_node(struct f2fs_sb_info *sbi,
 258                                 struct extent_tree *et, struct extent_node *en)
 259 {
 260         rb_erase_cached(&en->rb_node, &et->root);
 261         atomic_dec(&et->node_cnt);
 262         atomic_dec(&sbi->total_ext_node);
 263
 264         if (et->cached_en == en)
 265                 et->cached_en = NULL;
 266         kmem_cache_free(extent_node_slab, en);
 267 }
 268
 269 /*
 270  * Flow to release an extent_node:
 271  * 1. list_del_init
 272  * 2. __detach_extent_node
 273  * 3. kmem_cache_free.
 274  */
 275 static void __release_extent_node(struct f2fs_sb_info *sbi,
 276                         struct extent_tree *et, struct extent_node *en)
 277 {
 278         spin_lock(&sbi->extent_lock);
 279         f2fs_bug_on(sbi, list_empty(&en->list));
 280         list_del_init(&en->list);
 281         spin_unlock(&sbi->extent_lock);
 282
 283         __detach_extent_node(sbi, et, en);
 284 }
 285
 286 static struct extent_tree *__grab_extent_tree(struct inode *inode)
 287 {
 288         struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
 289         struct extent_tree *et;
 290         nid_t ino = inode->i_ino;
 291
 292         mutex_lock(&sbi->extent_tree_lock);
 293         et = radix_tree_lookup(&sbi->extent_tree_root, ino);
 294         if (!et) {
 295                 et = f2fs_kmem_cache_alloc(extent_tree_slab, GFP_NOFS);
 296                 f2fs_radix_tree_insert(&sbi->extent_tree_root, ino, et);
 297                 memset(et, 0, sizeof(struct extent_tree));
 298                 et->ino = ino;
 299                 et->root = RB_ROOT_CACHED;
 300                 et->cached_en = NULL;
 301                 rwlock_init(&et->lock);
 302                 INIT_LIST_HEAD(&et->list);
 303                 atomic_set(&et->node_cnt, 0);
 304                 atomic_inc(&sbi->total_ext_tree);
 305         } else {
 306                 atomic_dec(&sbi->total_zombie_tree);
 307                 list_del_init(&et->list);
 308         }
 309         mutex_unlock(&sbi->extent_tree_lock);
 310
 311         /* never died until evict_inode */
 312         F2FS_I(inode)->extent_tree = et;
 313
 314         return et;
 315 }
 316
 317 static struct extent_node *__init_extent_tree(struct f2fs_sb_info *sbi,
 318                                 struct extent_tree *et, struct extent_info *ei)
 319 {
 320         struct rb_node **p = &et->root.rb_root.rb_node;
 321         struct extent_node *en;
 322
 323         en = __attach_extent_node(sbi, et, ei, NULL, p, true);
 324         if (!en)
 325                 return NULL;
 326
 327         et->largest = en->ei;
 328         et->cached_en = en;
 329         return en;
 330 }
 331
 332 static unsigned int __free_extent_tree(struct f2fs_sb_info *sbi,
 333                                         struct extent_tree *et)
 334 {
 335         struct rb_node *node, *next;
 336         struct extent_node *en;
 337         unsigned int count = atomic_read(&et->node_cnt);
 338
 339         node = rb_first_cached(&et->root);
 340         while (node) {
 341                 next = rb_next(node);
 342                 en = rb_entry(node, struct extent_node, rb_node);
 343                 __release_extent_node(sbi, et, en);
 344                 node = next;
 345         }
 346
 347         return count - atomic_read(&et->node_cnt);
 348 }
 349
 350 static void __drop_largest_extent(struct extent_tree *et,
 351                                         pgoff_t fofs, unsigned int len)
 352 {
 353         if (fofs < et->largest.fofs + et->largest.len &&
 354                         fofs + len > et->largest.fofs) {
 355                 et->largest.len = 0;
 356                 et->largest_updated = true;
 357         }
 358 }
 359
 360 /* return true, if inode page is changed */
 361 static void __f2fs_init_extent_tree(struct inode *inode, struct page *ipage)
 362 {
 363         struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
 364         struct f2fs_extent *i_ext = ipage ? &F2FS_INODE(ipage)->i_ext : NULL;
 365         struct extent_tree *et;
 366         struct extent_node *en;
 367         struct extent_info ei;
 368
 369         if (!f2fs_may_extent_tree(inode)) {
 370                 /* drop largest extent */
 371                 if (i_ext && i_ext->len) {
 372                         f2fs_wait_on_page_writeback(ipage, NODE, true, true);
 373                         i_ext->len = 0;
 374                         set_page_dirty(ipage);
 375                         return;
 376                 }
 377                 return;
 378         }
 379
 380         et = __grab_extent_tree(inode);
 381
 382         if (!i_ext || !i_ext->len)
 383                 return;
 384
 385         get_extent_info(&ei, i_ext);
 386
 387         write_lock(&et->lock);
 388         if (atomic_read(&et->node_cnt))
 389                 goto out;
 390
 391         en = __init_extent_tree(sbi, et, &ei);
 392         if (en) {
 393                 spin_lock(&sbi->extent_lock);
 394                 list_add_tail(&en->list, &sbi->extent_list);
 395                 spin_unlock(&sbi->extent_lock);
 396         }
 397 out:
 398         write_unlock(&et->lock);
 399 }
 400
 401 void f2fs_init_extent_tree(struct inode *inode, struct page *ipage)
 402 {
 403         __f2fs_init_extent_tree(inode, ipage);
 404
 405         if (!F2FS_I(inode)->extent_tree)
 406                 set_inode_flag(inode, FI_NO_EXTENT);
 407 }
 408
 409 static bool f2fs_lookup_extent_tree(struct inode *inode, pgoff_t pgofs,
 410                                                         struct extent_info *ei)
 411 {
 412         struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
 413         struct extent_tree *et = F2FS_I(inode)->extent_tree;
 414         struct extent_node *en;
 415         bool ret = false;
 416
 417         f2fs_bug_on(sbi, !et);
 418
 419         trace_f2fs_lookup_extent_tree_start(inode, pgofs);
 420
 421         read_lock(&et->lock);
 422
 423         if (et->largest.fofs <= pgofs &&
 424                         et->largest.fofs + et->largest.len > pgofs) {
 425                 *ei = et->largest;
 426                 ret = true;
 427                 stat_inc_largest_node_hit(sbi);
 428                 goto out;
 429         }
 430
 431         en = (struct extent_node *)f2fs_lookup_rb_tree(&et->root,
 432                                 (struct rb_entry *)et->cached_en, pgofs);
 433         if (!en)
 434                 goto out;
 435
 436         if (en == et->cached_en)
 437                 stat_inc_cached_node_hit(sbi);
 438         else
 439                 stat_inc_rbtree_node_hit(sbi);
 440
 441         *ei = en->ei;
 442         spin_lock(&sbi->extent_lock);
 443         if (!list_empty(&en->list)) {
 444                 list_move_tail(&en->list, &sbi->extent_list);
 445                 et->cached_en = en;
 446         }
 447         spin_unlock(&sbi->extent_lock);
 448         ret = true;
 449 out:
 450         stat_inc_total_hit(sbi);
 451         read_unlock(&et->lock);
 452
 453         trace_f2fs_lookup_extent_tree_end(inode, pgofs, ei);
 454         return ret;
 455 }
 456
 457 static struct extent_node *__try_merge_extent_node(struct f2fs_sb_info *sbi,
 458                                 struct extent_tree *et, struct extent_info *ei,
 459                                 struct extent_node *prev_ex,
 460                                 struct extent_node *next_ex)
 461 {
 462         struct extent_node *en = NULL;
 463
 464         if (prev_ex && __is_back_mergeable(ei, &prev_ex->ei)) {
 465                 prev_ex->ei.len += ei->len;
 466                 ei = &prev_ex->ei;
 467                 en = prev_ex;
 468         }
 469
 470         if (next_ex && __is_front_mergeable(ei, &next_ex->ei)) {
 471                 next_ex->ei.fofs = ei->fofs;
 472                 next_ex->ei.blk = ei->blk;
 473                 next_ex->ei.len += ei->len;
 474                 if (en)
 475                         __release_extent_node(sbi, et, prev_ex);
 476
 477                 en = next_ex;
 478         }
 479
 480         if (!en)
 481                 return NULL;
 482
 483         __try_update_largest_extent(et, en);
 484
 485         spin_lock(&sbi->extent_lock);
 486         if (!list_empty(&en->list)) {
 487                 list_move_tail(&en->list, &sbi->extent_list);
 488                 et->cached_en = en;
 489         }
 490         spin_unlock(&sbi->extent_lock);
 491         return en;
 492 }
 493
 494 static struct extent_node *__insert_extent_tree(struct f2fs_sb_info *sbi,
 495                                 struct extent_tree *et, struct extent_info *ei,
 496                                 struct rb_node **insert_p,
 497                                 struct rb_node *insert_parent,
 498                                 bool leftmost)
 499 {
 500         struct rb_node **p;
 501         struct rb_node *parent = NULL;
 502         struct extent_node *en = NULL;
 503
 504         if (insert_p && insert_parent) {
 505                 parent = insert_parent;
 506                 p = insert_p;
 507                 goto do_insert;
 508         }
 509
 510         leftmost = true;
 511
 512         p = f2fs_lookup_rb_tree_for_insert(sbi, &et->root, &parent,
 513                                                 ei->fofs, &leftmost);
 514 do_insert:
 515         en = __attach_extent_node(sbi, et, ei, parent, p, leftmost);
 516         if (!en)
 517                 return NULL;
 518
 519         __try_update_largest_extent(et, en);
 520
 521         /* update in global extent list */
 522         spin_lock(&sbi->extent_lock);
 523         list_add_tail(&en->list, &sbi->extent_list);
 524         et->cached_en = en;
 525         spin_unlock(&sbi->extent_lock);
 526         return en;
 527 }
 528
 529 static void f2fs_update_extent_tree_range(struct inode *inode,
 530                                 pgoff_t fofs, block_t blkaddr, unsigned int len)
 531 {
 532         struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
 533         struct extent_tree *et = F2FS_I(inode)->extent_tree;
 534         struct extent_node *en = NULL, *en1 = NULL;
 535         struct extent_node *prev_en = NULL, *next_en = NULL;
 536         struct extent_info ei, dei, prev;
 537         struct rb_node **insert_p = NULL, *insert_parent = NULL;
 538         unsigned int end = fofs + len;
 539         unsigned int pos = (unsigned int)fofs;
 540         bool updated = false;
 541         bool leftmost = false;
 542
 543         if (!et)
 544                 return;
 545
 546         trace_f2fs_update_extent_tree_range(inode, fofs, blkaddr, len);
 547
 548         write_lock(&et->lock);
 549
 550         if (is_inode_flag_set(inode, FI_NO_EXTENT)) {
 551                 write_unlock(&et->lock);
 552                 return;
 553         }
 554
 555         prev = et->largest;
 556         dei.len = 0;
 557
 558         /*
 559          * drop largest extent before lookup, in case it's already
 560          * been shrunk from extent tree
 561          */
 562         __drop_largest_extent(et, fofs, len);
 563
 564         /* 1. lookup first extent node in range [fofs, fofs + len - 1] */
 565         en = (struct extent_node *)f2fs_lookup_rb_tree_ret(&et->root,
 566                                         (struct rb_entry *)et->cached_en, fofs,
 567                                         (struct rb_entry **)&prev_en,
 568                                         (struct rb_entry **)&next_en,
 569                                         &insert_p, &insert_parent, false,
 570                                         &leftmost);
 571         if (!en)
 572                 en = next_en;
 573
 574         /* 2. invlidate all extent nodes in range [fofs, fofs + len - 1] */
 575         while (en && en->ei.fofs < end) {
 576                 unsigned int org_end;
 577                 int parts = 0;  /* # of parts current extent split into */
 578
 579                 next_en = en1 = NULL;
 580
 581                 dei = en->ei;
 582                 org_end = dei.fofs + dei.len;
 583                 f2fs_bug_on(sbi, pos >= org_end);
 584
 585                 if (pos > dei.fofs &&   pos - dei.fofs >= F2FS_MIN_EXTENT_LEN) {
 586                         en->ei.len = pos - en->ei.fofs;
 587                         prev_en = en;
 588                         parts = 1;
 589                 }
 590
 591                 if (end < org_end && org_end - end >= F2FS_MIN_EXTENT_LEN) {
 592                         if (parts) {
 593                                 set_extent_info(&ei, end,
 594                                                 end - dei.fofs + dei.blk,
 595                                                 org_end - end);
 596                                 en1 = __insert_extent_tree(sbi, et, &ei,
 597                                                         NULL, NULL, true);
 598                                 next_en = en1;
 599                         } else {
 600                                 en->ei.fofs = end;
 601                                 en->ei.blk += end - dei.fofs;
 602                                 en->ei.len -= end - dei.fofs;
 603                                 next_en = en;
 604                         }
 605                         parts++;
 606                 }
 607
 608                 if (!next_en) {
 609                         struct rb_node *node = rb_next(&en->rb_node);
 610
 611                         next_en = rb_entry_safe(node, struct extent_node,
 612                                                 rb_node);
 613                 }
 614
 615                 if (parts)
 616                         __try_update_largest_extent(et, en);
 617                 else
 618                         __release_extent_node(sbi, et, en);
 619
 620                 /*
 621                  * if original extent is split into zero or two parts, extent
 622                  * tree has been altered by deletion or insertion, therefore
 623                  * invalidate pointers regard to tree.
 624                  */
 625                 if (parts != 1) {
 626                         insert_p = NULL;
 627                         insert_parent = NULL;
 628                 }
 629                 en = next_en;
 630         }
 631
 632         /* 3. update extent in extent cache */
 633         if (blkaddr) {
 634
 635                 set_extent_info(&ei, fofs, blkaddr, len);
 636                 if (!__try_merge_extent_node(sbi, et, &ei, prev_en, next_en))
 637                         __insert_extent_tree(sbi, et, &ei,
 638                                         insert_p, insert_parent, leftmost);
 639
 640                 /* give up extent_cache, if split and small updates happen */
 641                 if (dei.len >= 1 &&
 642                                 prev.len < F2FS_MIN_EXTENT_LEN &&
 643                                 et->largest.len < F2FS_MIN_EXTENT_LEN) {
 644                         et->largest.len = 0;
 645                         et->largest_updated = true;
 646                         set_inode_flag(inode, FI_NO_EXTENT);
 647                 }
 648         }
 649
 650         if (is_inode_flag_set(inode, FI_NO_EXTENT))
 651                 __free_extent_tree(sbi, et);
 652
 653         if (et->largest_updated) {
 654                 et->largest_updated = false;
 655                 updated = true;
 656         }
 657
 658         write_unlock(&et->lock);
 659
 660         if (updated)
 661                 f2fs_mark_inode_dirty_sync(inode, true);
 662 }
 663
 664 unsigned int f2fs_shrink_extent_tree(struct f2fs_sb_info *sbi, int nr_shrink)
 665 {
 666         struct extent_tree *et, *next;
 667         struct extent_node *en;
 668         unsigned int node_cnt = 0, tree_cnt = 0;
 669         int remained;
 670
 671         if (!test_opt(sbi, EXTENT_CACHE))
 672                 return 0;
 673
 674         if (!atomic_read(&sbi->total_zombie_tree))
 675                 goto free_node;
 676
 677         if (!mutex_trylock(&sbi->extent_tree_lock))
 678                 goto out;
 679
 680         /* 1. remove unreferenced extent tree */
 681         list_for_each_entry_safe(et, next, &sbi->zombie_list, list) {
 682                 if (atomic_read(&et->node_cnt)) {
 683                         write_lock(&et->lock);
 684                         node_cnt += __free_extent_tree(sbi, et);
 685                         write_unlock(&et->lock);
 686                 }
 687                 f2fs_bug_on(sbi, atomic_read(&et->node_cnt));
 688                 list_del_init(&et->list);
 689                 radix_tree_delete(&sbi->extent_tree_root, et->ino);
 690                 kmem_cache_free(extent_tree_slab, et);
 691                 atomic_dec(&sbi->total_ext_tree);
 692                 atomic_dec(&sbi->total_zombie_tree);
 693                 tree_cnt++;
 694
 695                 if (node_cnt + tree_cnt >= nr_shrink)
 696                         goto unlock_out;
 697                 cond_resched();
 698         }
 699         mutex_unlock(&sbi->extent_tree_lock);
 700
 701 free_node:
 702         /* 2. remove LRU extent entries */
 703         if (!mutex_trylock(&sbi->extent_tree_lock))
 704                 goto out;
 705
 706         remained = nr_shrink - (node_cnt + tree_cnt);
 707
 708         spin_lock(&sbi->extent_lock);
 709         for (; remained > 0; remained--) {
 710                 if (list_empty(&sbi->extent_list))
 711                         break;
 712                 en = list_first_entry(&sbi->extent_list,
 713                                         struct extent_node, list);
 714                 et = en->et;
 715                 if (!write_trylock(&et->lock)) {
 716                         /* refresh this extent node's position in extent list */
 717                         list_move_tail(&en->list, &sbi->extent_list);
 718                         continue;
 719                 }
 720
 721                 list_del_init(&en->list);
 722                 spin_unlock(&sbi->extent_lock);
 723
 724                 __detach_extent_node(sbi, et, en);
 725
 726                 write_unlock(&et->lock);
 727                 node_cnt++;
 728                 spin_lock(&sbi->extent_lock);
 729         }
 730         spin_unlock(&sbi->extent_lock);
 731
 732 unlock_out:
 733         mutex_unlock(&sbi->extent_tree_lock);
 734 out:
 735         trace_f2fs_shrink_extent_tree(sbi, node_cnt, tree_cnt);
 736
 737         return node_cnt + tree_cnt;
 738 }
 739
 740 unsigned int f2fs_destroy_extent_node(struct inode *inode)
 741 {
 742         struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
 743         struct extent_tree *et = F2FS_I(inode)->extent_tree;
 744         unsigned int node_cnt = 0;
 745
 746         if (!et || !atomic_read(&et->node_cnt))
 747                 return 0;
 748
 749         write_lock(&et->lock);
 750         node_cnt = __free_extent_tree(sbi, et);
 751         write_unlock(&et->lock);
 752
 753         return node_cnt;
 754 }
 755
 756 void f2fs_drop_extent_tree(struct inode *inode)
 757 {
 758         struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
 759         struct extent_tree *et = F2FS_I(inode)->extent_tree;
 760         bool updated = false;
 761
 762         if (!f2fs_may_extent_tree(inode))
 763                 return;
 764
 765         set_inode_flag(inode, FI_NO_EXTENT);
 766
 767         write_lock(&et->lock);
 768         __free_extent_tree(sbi, et);
 769         if (et->largest.len) {
 770                 et->largest.len = 0;
 771                 updated = true;
 772         }
 773         write_unlock(&et->lock);
 774         if (updated)
 775                 f2fs_mark_inode_dirty_sync(inode, true);
 776 }
 777
 778 void f2fs_destroy_extent_tree(struct inode *inode)
 779 {
 780         struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
 781         struct extent_tree *et = F2FS_I(inode)->extent_tree;
 782         unsigned int node_cnt = 0;
 783
 784         if (!et)
 785                 return;
 786
 787         if (inode->i_nlink && !is_bad_inode(inode) &&
 788                                         atomic_read(&et->node_cnt)) {
 789                 mutex_lock(&sbi->extent_tree_lock);
 790                 list_add_tail(&et->list, &sbi->zombie_list);
 791                 atomic_inc(&sbi->total_zombie_tree);
 792                 mutex_unlock(&sbi->extent_tree_lock);
 793                 return;
 794         }
 795
 796         /* free all extent info belong to this extent tree */
 797         node_cnt = f2fs_destroy_extent_node(inode);
 798
 799         /* delete extent tree entry in radix tree */
 800         mutex_lock(&sbi->extent_tree_lock);
 801         f2fs_bug_on(sbi, atomic_read(&et->node_cnt));
 802         radix_tree_delete(&sbi->extent_tree_root, inode->i_ino);
 803         kmem_cache_free(extent_tree_slab, et);
 804         atomic_dec(&sbi->total_ext_tree);
 805         mutex_unlock(&sbi->extent_tree_lock);
 806
 807         F2FS_I(inode)->extent_tree = NULL;
 808
 809         trace_f2fs_destroy_extent_tree(inode, node_cnt);
 810 }
 811
 812 bool f2fs_lookup_extent_cache(struct inode *inode, pgoff_t pgofs,
 813                                         struct extent_info *ei)
 814 {
 815         if (!f2fs_may_extent_tree(inode))
 816                 return false;
 817
 818         return f2fs_lookup_extent_tree(inode, pgofs, ei);
 819 }
 820
 821 void f2fs_update_extent_cache(struct dnode_of_data *dn)
 822 {
 823         pgoff_t fofs;
 824         block_t blkaddr;
 825
 826         if (!f2fs_may_extent_tree(dn->inode))
 827                 return;
 828
 829         if (dn->data_blkaddr == NEW_ADDR)
 830                 blkaddr = NULL_ADDR;
 831         else
 832                 blkaddr = dn->data_blkaddr;
 833
 834         fofs = f2fs_start_bidx_of_node(ofs_of_node(dn->node_page), dn->inode) +
 835                                                                 dn->ofs_in_node;
 836         f2fs_update_extent_tree_range(dn->inode, fofs, blkaddr, 1);
 837 }
 838
 839 void f2fs_update_extent_cache_range(struct dnode_of_data *dn,
 840                                 pgoff_t fofs, block_t blkaddr, unsigned int len)
 841
 842 {
 843         if (!f2fs_may_extent_tree(dn->inode))
 844                 return;
 845
 846         f2fs_update_extent_tree_range(dn->inode, fofs, blkaddr, len);
 847 }
 848
 849 void f2fs_init_extent_cache_info(struct f2fs_sb_info *sbi)
 850 {
 851         INIT_RADIX_TREE(&sbi->extent_tree_root, GFP_NOIO);
 852         mutex_init(&sbi->extent_tree_lock);
 853         INIT_LIST_HEAD(&sbi->extent_list);
 854         spin_lock_init(&sbi->extent_lock);
 855         atomic_set(&sbi->total_ext_tree, 0);
 856         INIT_LIST_HEAD(&sbi->zombie_list);
 857         atomic_set(&sbi->total_zombie_tree, 0);
 858         atomic_set(&sbi->total_ext_node, 0);
 859 }
 860
 861 int __init f2fs_create_extent_cache(void)
 862 {
 863         extent_tree_slab = f2fs_kmem_cache_create("f2fs_extent_tree",
 864                         sizeof(struct extent_tree));
 865         if (!extent_tree_slab)
 866                 return -ENOMEM;
 867         extent_node_slab = f2fs_kmem_cache_create("f2fs_extent_node",
 868                         sizeof(struct extent_node));
 869         if (!extent_node_slab) {
 870                 kmem_cache_destroy(extent_tree_slab);
 871                 return -ENOMEM;
 872         }
 873         return 0;
 874 }
 875
 876 void f2fs_destroy_extent_cache(void)
 877 {
 878         kmem_cache_destroy(extent_node_slab);
 879         kmem_cache_destroy(extent_tree_slab);
 880 }