fs/f2fs/node.c

   1 /*
   2  * fs/f2fs/node.c
   3  *
   4  * Copyright (c) 2012 Samsung Electronics Co., Ltd.
   5  *             http://www.samsung.com/
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  */
  11 #include <linux/fs.h>
  12 #include <linux/f2fs_fs.h>
  13 #include <linux/mpage.h>
  14 #include <linux/backing-dev.h>
  15 #include <linux/blkdev.h>
  16 #include <linux/pagevec.h>
  17 #include <linux/swap.h>
  18
  19 #include "f2fs.h"
  20 #include "node.h"
  21 #include "segment.h"
  22 #include <trace/events/f2fs.h>
  23
  24 static struct kmem_cache *nat_entry_slab;
  25 static struct kmem_cache *free_nid_slab;
  26
  27 static void clear_node_page_dirty(struct page *page)
  28 {
  29         struct address_space *mapping = page->mapping;
  30         struct f2fs_sb_info *sbi = F2FS_SB(mapping->host->i_sb);
  31         unsigned int long flags;
  32
  33         if (PageDirty(page)) {
  34                 spin_lock_irqsave(&mapping->tree_lock, flags);
  35                 radix_tree_tag_clear(&mapping->page_tree,
  36                                 page_index(page),
  37                                 PAGECACHE_TAG_DIRTY);
  38                 spin_unlock_irqrestore(&mapping->tree_lock, flags);
  39
  40                 clear_page_dirty_for_io(page);
  41                 dec_page_count(sbi, F2FS_DIRTY_NODES);
  42         }
  43         ClearPageUptodate(page);
  44 }
  45
  46 static struct page *get_current_nat_page(struct f2fs_sb_info *sbi, nid_t nid)
  47 {
  48         pgoff_t index = current_nat_addr(sbi, nid);
  49         return get_meta_page(sbi, index);
  50 }
  51
  52 static struct page *get_next_nat_page(struct f2fs_sb_info *sbi, nid_t nid)
  53 {
  54         struct page *src_page;
  55         struct page *dst_page;
  56         pgoff_t src_off;
  57         pgoff_t dst_off;
  58         void *src_addr;
  59         void *dst_addr;
  60         struct f2fs_nm_info *nm_i = NM_I(sbi);
  61
  62         src_off = current_nat_addr(sbi, nid);
  63         dst_off = next_nat_addr(sbi, src_off);
  64
  65         /* get current nat block page with lock */
  66         src_page = get_meta_page(sbi, src_off);
  67
  68         /* Dirty src_page means that it is already the new target NAT page. */
  69         if (PageDirty(src_page))
  70                 return src_page;
  71
  72         dst_page = grab_meta_page(sbi, dst_off);
  73
  74         src_addr = page_address(src_page);
  75         dst_addr = page_address(dst_page);
  76         memcpy(dst_addr, src_addr, PAGE_CACHE_SIZE);
  77         set_page_dirty(dst_page);
  78         f2fs_put_page(src_page, 1);
  79
  80         set_to_next_nat(nm_i, nid);
  81
  82         return dst_page;
  83 }
  84
  85 /*
  86  * Readahead NAT pages
  87  */
  88 static void ra_nat_pages(struct f2fs_sb_info *sbi, int nid)
  89 {
  90         struct address_space *mapping = sbi->meta_inode->i_mapping;
  91         struct f2fs_nm_info *nm_i = NM_I(sbi);
  92         struct page *page;
  93         pgoff_t index;
  94         int i;
  95
  96         for (i = 0; i < FREE_NID_PAGES; i++, nid += NAT_ENTRY_PER_BLOCK) {
  97                 if (nid >= nm_i->max_nid)
  98                         nid = 0;
  99                 index = current_nat_addr(sbi, nid);
 100
 101                 page = grab_cache_page(mapping, index);
 102                 if (!page)
 103                         continue;
 104                 if (PageUptodate(page)) {
 105                         f2fs_put_page(page, 1);
 106                         continue;
 107                 }
 108                 if (f2fs_readpage(sbi, page, index, READ))
 109                         continue;
 110
 111                 f2fs_put_page(page, 0);
 112         }
 113 }
 114
 115 static struct nat_entry *__lookup_nat_cache(struct f2fs_nm_info *nm_i, nid_t n)
 116 {
 117         return radix_tree_lookup(&nm_i->nat_root, n);
 118 }
 119
 120 static unsigned int __gang_lookup_nat_cache(struct f2fs_nm_info *nm_i,
 121                 nid_t start, unsigned int nr, struct nat_entry **ep)
 122 {
 123         return radix_tree_gang_lookup(&nm_i->nat_root, (void **)ep, start, nr);
 124 }
 125
 126 static void __del_from_nat_cache(struct f2fs_nm_info *nm_i, struct nat_entry *e)
 127 {
 128         list_del(&e->list);
 129         radix_tree_delete(&nm_i->nat_root, nat_get_nid(e));
 130         nm_i->nat_cnt--;
 131         kmem_cache_free(nat_entry_slab, e);
 132 }
 133
 134 int is_checkpointed_node(struct f2fs_sb_info *sbi, nid_t nid)
 135 {
 136         struct f2fs_nm_info *nm_i = NM_I(sbi);
 137         struct nat_entry *e;
 138         int is_cp = 1;
 139
 140         read_lock(&nm_i->nat_tree_lock);
 141         e = __lookup_nat_cache(nm_i, nid);
 142         if (e && !e->checkpointed)
 143                 is_cp = 0;
 144         read_unlock(&nm_i->nat_tree_lock);
 145         return is_cp;
 146 }
 147
 148 static struct nat_entry *grab_nat_entry(struct f2fs_nm_info *nm_i, nid_t nid)
 149 {
 150         struct nat_entry *new;
 151
 152         new = kmem_cache_alloc(nat_entry_slab, GFP_ATOMIC);
 153         if (!new)
 154                 return NULL;
 155         if (radix_tree_insert(&nm_i->nat_root, nid, new)) {
 156                 kmem_cache_free(nat_entry_slab, new);
 157                 return NULL;
 158         }
 159         memset(new, 0, sizeof(struct nat_entry));
 160         nat_set_nid(new, nid);
 161         list_add_tail(&new->list, &nm_i->nat_entries);
 162         nm_i->nat_cnt++;
 163         return new;
 164 }
 165
 166 static void cache_nat_entry(struct f2fs_nm_info *nm_i, nid_t nid,
 167                                                 struct f2fs_nat_entry *ne)
 168 {
 169         struct nat_entry *e;
 170 retry:
 171         write_lock(&nm_i->nat_tree_lock);
 172         e = __lookup_nat_cache(nm_i, nid);
 173         if (!e) {
 174                 e = grab_nat_entry(nm_i, nid);
 175                 if (!e) {
 176                         write_unlock(&nm_i->nat_tree_lock);
 177                         goto retry;
 178                 }
 179                 nat_set_blkaddr(e, le32_to_cpu(ne->block_addr));
 180                 nat_set_ino(e, le32_to_cpu(ne->ino));
 181                 nat_set_version(e, ne->version);
 182                 e->checkpointed = true;
 183         }
 184         write_unlock(&nm_i->nat_tree_lock);
 185 }
 186
 187 static void set_node_addr(struct f2fs_sb_info *sbi, struct node_info *ni,
 188                         block_t new_blkaddr)
 189 {
 190         struct f2fs_nm_info *nm_i = NM_I(sbi);
 191         struct nat_entry *e;
 192 retry:
 193         write_lock(&nm_i->nat_tree_lock);
 194         e = __lookup_nat_cache(nm_i, ni->nid);
 195         if (!e) {
 196                 e = grab_nat_entry(nm_i, ni->nid);
 197                 if (!e) {
 198                         write_unlock(&nm_i->nat_tree_lock);
 199                         goto retry;
 200                 }
 201                 e->ni = *ni;
 202                 e->checkpointed = true;
 203                 BUG_ON(ni->blk_addr == NEW_ADDR);
 204         } else if (new_blkaddr == NEW_ADDR) {
 205                 /*
 206                  * when nid is reallocated,
 207                  * previous nat entry can be remained in nat cache.
 208                  * So, reinitialize it with new information.
 209                  */
 210                 e->ni = *ni;
 211                 BUG_ON(ni->blk_addr != NULL_ADDR);
 212         }
 213
 214         if (new_blkaddr == NEW_ADDR)
 215                 e->checkpointed = false;
 216
 217         /* sanity check */
 218         BUG_ON(nat_get_blkaddr(e) != ni->blk_addr);
 219         BUG_ON(nat_get_blkaddr(e) == NULL_ADDR &&
 220                         new_blkaddr == NULL_ADDR);
 221         BUG_ON(nat_get_blkaddr(e) == NEW_ADDR &&
 222                         new_blkaddr == NEW_ADDR);
 223         BUG_ON(nat_get_blkaddr(e) != NEW_ADDR &&
 224                         nat_get_blkaddr(e) != NULL_ADDR &&
 225                         new_blkaddr == NEW_ADDR);
 226
 227         /* increament version no as node is removed */
 228         if (nat_get_blkaddr(e) != NEW_ADDR && new_blkaddr == NULL_ADDR) {
 229                 unsigned char version = nat_get_version(e);
 230                 nat_set_version(e, inc_node_version(version));
 231         }
 232
 233         /* change address */
 234         nat_set_blkaddr(e, new_blkaddr);
 235         __set_nat_cache_dirty(nm_i, e);
 236         write_unlock(&nm_i->nat_tree_lock);
 237 }
 238
 239 static int try_to_free_nats(struct f2fs_sb_info *sbi, int nr_shrink)
 240 {
 241         struct f2fs_nm_info *nm_i = NM_I(sbi);
 242
 243         if (nm_i->nat_cnt < 2 * NM_WOUT_THRESHOLD)
 244                 return 0;
 245
 246         write_lock(&nm_i->nat_tree_lock);
 247         while (nr_shrink && !list_empty(&nm_i->nat_entries)) {
 248                 struct nat_entry *ne;
 249                 ne = list_first_entry(&nm_i->nat_entries,
 250                                         struct nat_entry, list);
 251                 __del_from_nat_cache(nm_i, ne);
 252                 nr_shrink--;
 253         }
 254         write_unlock(&nm_i->nat_tree_lock);
 255         return nr_shrink;
 256 }
 257
 258 /*
 259  * This function returns always success
 260  */
 261 void get_node_info(struct f2fs_sb_info *sbi, nid_t nid, struct node_info *ni)
 262 {
 263         struct f2fs_nm_info *nm_i = NM_I(sbi);
 264         struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_HOT_DATA);
 265         struct f2fs_summary_block *sum = curseg->sum_blk;
 266         nid_t start_nid = START_NID(nid);
 267         struct f2fs_nat_block *nat_blk;
 268         struct page *page = NULL;
 269         struct f2fs_nat_entry ne;
 270         struct nat_entry *e;
 271         int i;
 272
 273         memset(&ne, 0, sizeof(struct f2fs_nat_entry));
 274         ni->nid = nid;
 275
 276         /* Check nat cache */
 277         read_lock(&nm_i->nat_tree_lock);
 278         e = __lookup_nat_cache(nm_i, nid);
 279         if (e) {
 280                 ni->ino = nat_get_ino(e);
 281                 ni->blk_addr = nat_get_blkaddr(e);
 282                 ni->version = nat_get_version(e);
 283         }
 284         read_unlock(&nm_i->nat_tree_lock);
 285         if (e)
 286                 return;
 287
 288         /* Check current segment summary */
 289         mutex_lock(&curseg->curseg_mutex);
 290         i = lookup_journal_in_cursum(sum, NAT_JOURNAL, nid, 0);
 291         if (i >= 0) {
 292                 ne = nat_in_journal(sum, i);
 293                 node_info_from_raw_nat(ni, &ne);
 294         }
 295         mutex_unlock(&curseg->curseg_mutex);
 296         if (i >= 0)
 297                 goto cache;
 298
 299         /* Fill node_info from nat page */
 300         page = get_current_nat_page(sbi, start_nid);
 301         nat_blk = (struct f2fs_nat_block *)page_address(page);
 302         ne = nat_blk->entries[nid - start_nid];
 303         node_info_from_raw_nat(ni, &ne);
 304         f2fs_put_page(page, 1);
 305 cache:
 306         /* cache nat entry */
 307         cache_nat_entry(NM_I(sbi), nid, &ne);
 308 }
 309
 310 /*
 311  * The maximum depth is four.
 312  * Offset[0] will have raw inode offset.
 313  */
 314 static int get_node_path(long block, int offset[4], unsigned int noffset[4])
 315 {
 316         const long direct_index = ADDRS_PER_INODE;
 317         const long direct_blks = ADDRS_PER_BLOCK;
 318         const long dptrs_per_blk = NIDS_PER_BLOCK;
 319         const long indirect_blks = ADDRS_PER_BLOCK * NIDS_PER_BLOCK;
 320         const long dindirect_blks = indirect_blks * NIDS_PER_BLOCK;
 321         int n = 0;
 322         int level = 0;
 323
 324         noffset[0] = 0;
 325
 326         if (block < direct_index) {
 327                 offset[n] = block;
 328                 goto got;
 329         }
 330         block -= direct_index;
 331         if (block < direct_blks) {
 332                 offset[n++] = NODE_DIR1_BLOCK;
 333                 noffset[n] = 1;
 334                 offset[n] = block;
 335                 level = 1;
 336                 goto got;
 337         }
 338         block -= direct_blks;
 339         if (block < direct_blks) {
 340                 offset[n++] = NODE_DIR2_BLOCK;
 341                 noffset[n] = 2;
 342                 offset[n] = block;
 343                 level = 1;
 344                 goto got;
 345         }
 346         block -= direct_blks;
 347         if (block < indirect_blks) {
 348                 offset[n++] = NODE_IND1_BLOCK;
 349                 noffset[n] = 3;
 350                 offset[n++] = block / direct_blks;
 351                 noffset[n] = 4 + offset[n - 1];
 352                 offset[n] = block % direct_blks;
 353                 level = 2;
 354                 goto got;
 355         }
 356         block -= indirect_blks;
 357         if (block < indirect_blks) {
 358                 offset[n++] = NODE_IND2_BLOCK;
 359                 noffset[n] = 4 + dptrs_per_blk;
 360                 offset[n++] = block / direct_blks;
 361                 noffset[n] = 5 + dptrs_per_blk + offset[n - 1];
 362                 offset[n] = block % direct_blks;
 363                 level = 2;
 364                 goto got;
 365         }
 366         block -= indirect_blks;
 367         if (block < dindirect_blks) {
 368                 offset[n++] = NODE_DIND_BLOCK;
 369                 noffset[n] = 5 + (dptrs_per_blk * 2);
 370                 offset[n++] = block / indirect_blks;
 371                 noffset[n] = 6 + (dptrs_per_blk * 2) +
 372                               offset[n - 1] * (dptrs_per_blk + 1);
 373                 offset[n++] = (block / direct_blks) % dptrs_per_blk;
 374                 noffset[n] = 7 + (dptrs_per_blk * 2) +
 375                               offset[n - 2] * (dptrs_per_blk + 1) +
 376                               offset[n - 1];
 377                 offset[n] = block % direct_blks;
 378                 level = 3;
 379                 goto got;
 380         } else {
 381                 BUG();
 382         }
 383 got:
 384         return level;
 385 }
 386
 387 /*
 388  * Caller should call f2fs_put_dnode(dn).
 389  * Also, it should grab and release a mutex by calling mutex_lock_op() and
 390  * mutex_unlock_op() only if ro is not set RDONLY_NODE.
 391  * In the case of RDONLY_NODE, we don't need to care about mutex.
 392  */
 393 int get_dnode_of_data(struct dnode_of_data *dn, pgoff_t index, int mode)
 394 {
 395         struct f2fs_sb_info *sbi = F2FS_SB(dn->inode->i_sb);
 396         struct page *npage[4];
 397         struct page *parent;
 398         int offset[4];
 399         unsigned int noffset[4];
 400         nid_t nids[4];
 401         int level, i;
 402         int err = 0;
 403
 404         level = get_node_path(index, offset, noffset);
 405
 406         nids[0] = dn->inode->i_ino;
 407         npage[0] = get_node_page(sbi, nids[0]);
 408         if (IS_ERR(npage[0]))
 409                 return PTR_ERR(npage[0]);
 410
 411         parent = npage[0];
 412         if (level != 0)
 413                 nids[1] = get_nid(parent, offset[0], true);
 414         dn->inode_page = npage[0];
 415         dn->inode_page_locked = true;
 416
 417         /* get indirect or direct nodes */
 418         for (i = 1; i <= level; i++) {
 419                 bool done = false;
 420
 421                 if (!nids[i] && mode == ALLOC_NODE) {
 422                         /* alloc new node */
 423                         if (!alloc_nid(sbi, &(nids[i]))) {
 424                                 err = -ENOSPC;
 425                                 goto release_pages;
 426                         }
 427
 428                         dn->nid = nids[i];
 429                         npage[i] = new_node_page(dn, noffset[i]);
 430                         if (IS_ERR(npage[i])) {
 431                                 alloc_nid_failed(sbi, nids[i]);
 432                                 err = PTR_ERR(npage[i]);
 433                                 goto release_pages;
 434                         }
 435
 436                         set_nid(parent, offset[i - 1], nids[i], i == 1);
 437                         alloc_nid_done(sbi, nids[i]);
 438                         done = true;
 439                 } else if (mode == LOOKUP_NODE_RA && i == level && level > 1) {
 440                         npage[i] = get_node_page_ra(parent, offset[i - 1]);
 441                         if (IS_ERR(npage[i])) {
 442                                 err = PTR_ERR(npage[i]);
 443                                 goto release_pages;
 444                         }
 445                         done = true;
 446                 }
 447                 if (i == 1) {
 448                         dn->inode_page_locked = false;
 449                         unlock_page(parent);
 450                 } else {
 451                         f2fs_put_page(parent, 1);
 452                 }
 453
 454                 if (!done) {
 455                         npage[i] = get_node_page(sbi, nids[i]);
 456                         if (IS_ERR(npage[i])) {
 457                                 err = PTR_ERR(npage[i]);
 458                                 f2fs_put_page(npage[0], 0);
 459                                 goto release_out;
 460                         }
 461                 }
 462                 if (i < level) {
 463                         parent = npage[i];
 464                         nids[i + 1] = get_nid(parent, offset[i], false);
 465                 }
 466         }
 467         dn->nid = nids[level];
 468         dn->ofs_in_node = offset[level];
 469         dn->node_page = npage[level];
 470         dn->data_blkaddr = datablock_addr(dn->node_page, dn->ofs_in_node);
 471         return 0;
 472
 473 release_pages:
 474         f2fs_put_page(parent, 1);
 475         if (i > 1)
 476                 f2fs_put_page(npage[0], 0);
 477 release_out:
 478         dn->inode_page = NULL;
 479         dn->node_page = NULL;
 480         return err;
 481 }
 482
 483 static void truncate_node(struct dnode_of_data *dn)
 484 {
 485         struct f2fs_sb_info *sbi = F2FS_SB(dn->inode->i_sb);
 486         struct node_info ni;
 487
 488         get_node_info(sbi, dn->nid, &ni);
 489         if (dn->inode->i_blocks == 0) {
 490                 BUG_ON(ni.blk_addr != NULL_ADDR);
 491                 goto invalidate;
 492         }
 493         BUG_ON(ni.blk_addr == NULL_ADDR);
 494
 495         /* Deallocate node address */
 496         invalidate_blocks(sbi, ni.blk_addr);
 497         dec_valid_node_count(sbi, dn->inode, 1);
 498         set_node_addr(sbi, &ni, NULL_ADDR);
 499
 500         if (dn->nid == dn->inode->i_ino) {
 501                 remove_orphan_inode(sbi, dn->nid);
 502                 dec_valid_inode_count(sbi);
 503         } else {
 504                 sync_inode_page(dn);
 505         }
 506 invalidate:
 507         clear_node_page_dirty(dn->node_page);
 508         F2FS_SET_SB_DIRT(sbi);
 509
 510         f2fs_put_page(dn->node_page, 1);
 511         dn->node_page = NULL;
 512         trace_f2fs_truncate_node(dn->inode, dn->nid, ni.blk_addr);
 513 }
 514
 515 static int truncate_dnode(struct dnode_of_data *dn)
 516 {
 517         struct f2fs_sb_info *sbi = F2FS_SB(dn->inode->i_sb);
 518         struct page *page;
 519
 520         if (dn->nid == 0)
 521                 return 1;
 522
 523         /* get direct node */
 524         page = get_node_page(sbi, dn->nid);
 525         if (IS_ERR(page) && PTR_ERR(page) == -ENOENT)
 526                 return 1;
 527         else if (IS_ERR(page))
 528                 return PTR_ERR(page);
 529
 530         /* Make dnode_of_data for parameter */
 531         dn->node_page = page;
 532         dn->ofs_in_node = 0;
 533         truncate_data_blocks(dn);
 534         truncate_node(dn);
 535         return 1;
 536 }
 537
 538 static int truncate_nodes(struct dnode_of_data *dn, unsigned int nofs,
 539                                                 int ofs, int depth)
 540 {
 541         struct f2fs_sb_info *sbi = F2FS_SB(dn->inode->i_sb);
 542         struct dnode_of_data rdn = *dn;
 543         struct page *page;
 544         struct f2fs_node *rn;
 545         nid_t child_nid;
 546         unsigned int child_nofs;
 547         int freed = 0;
 548         int i, ret;
 549
 550         if (dn->nid == 0)
 551                 return NIDS_PER_BLOCK + 1;
 552
 553         trace_f2fs_truncate_nodes_enter(dn->inode, dn->nid, dn->data_blkaddr);
 554
 555         page = get_node_page(sbi, dn->nid);
 556         if (IS_ERR(page)) {
 557                 trace_f2fs_truncate_nodes_exit(dn->inode, PTR_ERR(page));
 558                 return PTR_ERR(page);
 559         }
 560
 561         rn = (struct f2fs_node *)page_address(page);
 562         if (depth < 3) {
 563                 for (i = ofs; i < NIDS_PER_BLOCK; i++, freed++) {
 564                         child_nid = le32_to_cpu(rn->in.nid[i]);
 565                         if (child_nid == 0)
 566                                 continue;
 567                         rdn.nid = child_nid;
 568                         ret = truncate_dnode(&rdn);
 569                         if (ret < 0)
 570                                 goto out_err;
 571                         set_nid(page, i, 0, false);
 572                 }
 573         } else {
 574                 child_nofs = nofs + ofs * (NIDS_PER_BLOCK + 1) + 1;
 575                 for (i = ofs; i < NIDS_PER_BLOCK; i++) {
 576                         child_nid = le32_to_cpu(rn->in.nid[i]);
 577                         if (child_nid == 0) {
 578                                 child_nofs += NIDS_PER_BLOCK + 1;
 579                                 continue;
 580                         }
 581                         rdn.nid = child_nid;
 582                         ret = truncate_nodes(&rdn, child_nofs, 0, depth - 1);
 583                         if (ret == (NIDS_PER_BLOCK + 1)) {
 584                                 set_nid(page, i, 0, false);
 585                                 child_nofs += ret;
 586                         } else if (ret < 0 && ret != -ENOENT) {
 587                                 goto out_err;
 588                         }
 589                 }
 590                 freed = child_nofs;
 591         }
 592
 593         if (!ofs) {
 594                 /* remove current indirect node */
 595                 dn->node_page = page;
 596                 truncate_node(dn);
 597                 freed++;
 598         } else {
 599                 f2fs_put_page(page, 1);
 600         }
 601         trace_f2fs_truncate_nodes_exit(dn->inode, freed);
 602         return freed;
 603
 604 out_err:
 605         f2fs_put_page(page, 1);
 606         trace_f2fs_truncate_nodes_exit(dn->inode, ret);
 607         return ret;
 608 }
 609
 610 static int truncate_partial_nodes(struct dnode_of_data *dn,
 611                         struct f2fs_inode *ri, int *offset, int depth)
 612 {
 613         struct f2fs_sb_info *sbi = F2FS_SB(dn->inode->i_sb);
 614         struct page *pages[2];
 615         nid_t nid[3];
 616         nid_t child_nid;
 617         int err = 0;
 618         int i;
 619         int idx = depth - 2;
 620
 621         nid[0] = le32_to_cpu(ri->i_nid[offset[0] - NODE_DIR1_BLOCK]);
 622         if (!nid[0])
 623                 return 0;
 624
 625         /* get indirect nodes in the path */
 626         for (i = 0; i < depth - 1; i++) {
 627                 /* refernece count'll be increased */
 628                 pages[i] = get_node_page(sbi, nid[i]);
 629                 if (IS_ERR(pages[i])) {
 630                         depth = i + 1;
 631                         err = PTR_ERR(pages[i]);
 632                         goto fail;
 633                 }
 634                 nid[i + 1] = get_nid(pages[i], offset[i + 1], false);
 635         }
 636
 637         /* free direct nodes linked to a partial indirect node */
 638         for (i = offset[depth - 1]; i < NIDS_PER_BLOCK; i++) {
 639                 child_nid = get_nid(pages[idx], i, false);
 640                 if (!child_nid)
 641                         continue;
 642                 dn->nid = child_nid;
 643                 err = truncate_dnode(dn);
 644                 if (err < 0)
 645                         goto fail;
 646                 set_nid(pages[idx], i, 0, false);
 647         }
 648
 649         if (offset[depth - 1] == 0) {
 650                 dn->node_page = pages[idx];
 651                 dn->nid = nid[idx];
 652                 truncate_node(dn);
 653         } else {
 654                 f2fs_put_page(pages[idx], 1);
 655         }
 656         offset[idx]++;
 657         offset[depth - 1] = 0;
 658 fail:
 659         for (i = depth - 3; i >= 0; i--)
 660                 f2fs_put_page(pages[i], 1);
 661
 662         trace_f2fs_truncate_partial_nodes(dn->inode, nid, depth, err);
 663
 664         return err;
 665 }
 666
 667 /*
 668  * All the block addresses of data and nodes should be nullified.
 669  */
 670 int truncate_inode_blocks(struct inode *inode, pgoff_t from)
 671 {
 672         struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
 673         int err = 0, cont = 1;
 674         int level, offset[4], noffset[4];
 675         unsigned int nofs = 0;
 676         struct f2fs_node *rn;
 677         struct dnode_of_data dn;
 678         struct page *page;
 679
 680         trace_f2fs_truncate_inode_blocks_enter(inode, from);
 681
 682         level = get_node_path(from, offset, noffset);
 683
 684         page = get_node_page(sbi, inode->i_ino);
 685         if (IS_ERR(page)) {
 686                 trace_f2fs_truncate_inode_blocks_exit(inode, PTR_ERR(page));
 687                 return PTR_ERR(page);
 688         }
 689
 690         set_new_dnode(&dn, inode, page, NULL, 0);
 691         unlock_page(page);
 692
 693         rn = page_address(page);
 694         switch (level) {
 695         case 0:
 696         case 1:
 697                 nofs = noffset[1];
 698                 break;
 699         case 2:
 700                 nofs = noffset[1];
 701                 if (!offset[level - 1])
 702                         goto skip_partial;
 703                 err = truncate_partial_nodes(&dn, &rn->i, offset, level);
 704                 if (err < 0 && err != -ENOENT)
 705                         goto fail;
 706                 nofs += 1 + NIDS_PER_BLOCK;
 707                 break;
 708         case 3:
 709                 nofs = 5 + 2 * NIDS_PER_BLOCK;
 710                 if (!offset[level - 1])
 711                         goto skip_partial;
 712                 err = truncate_partial_nodes(&dn, &rn->i, offset, level);
 713                 if (err < 0 && err != -ENOENT)
 714                         goto fail;
 715                 break;
 716         default:
 717                 BUG();
 718         }
 719
 720 skip_partial:
 721         while (cont) {
 722                 dn.nid = le32_to_cpu(rn->i.i_nid[offset[0] - NODE_DIR1_BLOCK]);
 723                 switch (offset[0]) {
 724                 case NODE_DIR1_BLOCK:
 725                 case NODE_DIR2_BLOCK:
 726                         err = truncate_dnode(&dn);
 727                         break;
 728
 729                 case NODE_IND1_BLOCK:
 730                 case NODE_IND2_BLOCK:
 731                         err = truncate_nodes(&dn, nofs, offset[1], 2);
 732                         break;
 733
 734                 case NODE_DIND_BLOCK:
 735                         err = truncate_nodes(&dn, nofs, offset[1], 3);
 736                         cont = 0;
 737                         break;
 738
 739                 default:
 740                         BUG();
 741                 }
 742                 if (err < 0 && err != -ENOENT)
 743                         goto fail;
 744                 if (offset[1] == 0 &&
 745                                 rn->i.i_nid[offset[0] - NODE_DIR1_BLOCK]) {
 746                         lock_page(page);
 747                         wait_on_page_writeback(page);
 748                         rn->i.i_nid[offset[0] - NODE_DIR1_BLOCK] = 0;
 749                         set_page_dirty(page);
 750                         unlock_page(page);
 751                 }
 752                 offset[1] = 0;
 753                 offset[0]++;
 754                 nofs += err;
 755         }
 756 fail:
 757         f2fs_put_page(page, 0);
 758         trace_f2fs_truncate_inode_blocks_exit(inode, err);
 759         return err > 0 ? 0 : err;
 760 }
 761
 762 /*
 763  * Caller should grab and release a mutex by calling mutex_lock_op() and
 764  * mutex_unlock_op().
 765  */
 766 int remove_inode_page(struct inode *inode)
 767 {
 768         struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
 769         struct page *page;
 770         nid_t ino = inode->i_ino;
 771         struct dnode_of_data dn;
 772
 773         page = get_node_page(sbi, ino);
 774         if (IS_ERR(page))
 775                 return PTR_ERR(page);
 776
 777         if (F2FS_I(inode)->i_xattr_nid) {
 778                 nid_t nid = F2FS_I(inode)->i_xattr_nid;
 779                 struct page *npage = get_node_page(sbi, nid);
 780
 781                 if (IS_ERR(npage))
 782                         return PTR_ERR(npage);
 783
 784                 F2FS_I(inode)->i_xattr_nid = 0;
 785                 set_new_dnode(&dn, inode, page, npage, nid);
 786                 dn.inode_page_locked = 1;
 787                 truncate_node(&dn);
 788         }
 789
 790         /* 0 is possible, after f2fs_new_inode() is failed */
 791         BUG_ON(inode->i_blocks != 0 && inode->i_blocks != 1);
 792         set_new_dnode(&dn, inode, page, page, ino);
 793         truncate_node(&dn);
 794         return 0;
 795 }
 796
 797 int new_inode_page(struct inode *inode, const struct qstr *name)
 798 {
 799         struct page *page;
 800         struct dnode_of_data dn;
 801
 802         /* allocate inode page for new inode */
 803         set_new_dnode(&dn, inode, NULL, NULL, inode->i_ino);
 804         page = new_node_page(&dn, 0);
 805         init_dent_inode(name, page);
 806         if (IS_ERR(page))
 807                 return PTR_ERR(page);
 808         f2fs_put_page(page, 1);
 809         return 0;
 810 }
 811
 812 struct page *new_node_page(struct dnode_of_data *dn, unsigned int ofs)
 813 {
 814         struct f2fs_sb_info *sbi = F2FS_SB(dn->inode->i_sb);
 815         struct address_space *mapping = sbi->node_inode->i_mapping;
 816         struct node_info old_ni, new_ni;
 817         struct page *page;
 818         int err;
 819
 820         if (is_inode_flag_set(F2FS_I(dn->inode), FI_NO_ALLOC))
 821                 return ERR_PTR(-EPERM);
 822
 823         page = grab_cache_page(mapping, dn->nid);
 824         if (!page)
 825                 return ERR_PTR(-ENOMEM);
 826
 827         get_node_info(sbi, dn->nid, &old_ni);
 828
 829         SetPageUptodate(page);
 830         fill_node_footer(page, dn->nid, dn->inode->i_ino, ofs, true);
 831
 832         /* Reinitialize old_ni with new node page */
 833         BUG_ON(old_ni.blk_addr != NULL_ADDR);
 834         new_ni = old_ni;
 835         new_ni.ino = dn->inode->i_ino;
 836
 837         if (!inc_valid_node_count(sbi, dn->inode, 1)) {
 838                 err = -ENOSPC;
 839                 goto fail;
 840         }
 841         set_node_addr(sbi, &new_ni, NEW_ADDR);
 842         set_cold_node(dn->inode, page);
 843
 844         dn->node_page = page;
 845         sync_inode_page(dn);
 846         set_page_dirty(page);
 847         if (ofs == 0)
 848                 inc_valid_inode_count(sbi);
 849
 850         return page;
 851
 852 fail:
 853         clear_node_page_dirty(page);
 854         f2fs_put_page(page, 1);
 855         return ERR_PTR(err);
 856 }
 857
 858 /*
 859  * Caller should do after getting the following values.
 860  * 0: f2fs_put_page(page, 0)
 861  * LOCKED_PAGE: f2fs_put_page(page, 1)
 862  * error: nothing
 863  */
 864 static int read_node_page(struct page *page, int type)
 865 {
 866         struct f2fs_sb_info *sbi = F2FS_SB(page->mapping->host->i_sb);
 867         struct node_info ni;
 868
 869         get_node_info(sbi, page->index, &ni);
 870
 871         if (ni.blk_addr == NULL_ADDR) {
 872                 f2fs_put_page(page, 1);
 873                 return -ENOENT;
 874         }
 875
 876         if (PageUptodate(page))
 877                 return LOCKED_PAGE;
 878
 879         return f2fs_readpage(sbi, page, ni.blk_addr, type);
 880 }
 881
 882 /*
 883  * Readahead a node page
 884  */
 885 void ra_node_page(struct f2fs_sb_info *sbi, nid_t nid)
 886 {
 887         struct address_space *mapping = sbi->node_inode->i_mapping;
 888         struct page *apage;
 889         int err;
 890
 891         apage = find_get_page(mapping, nid);
 892         if (apage && PageUptodate(apage)) {
 893                 f2fs_put_page(apage, 0);
 894                 return;
 895         }
 896         f2fs_put_page(apage, 0);
 897
 898         apage = grab_cache_page(mapping, nid);
 899         if (!apage)
 900                 return;
 901
 902         err = read_node_page(apage, READA);
 903         if (err == 0)
 904                 f2fs_put_page(apage, 0);
 905         else if (err == LOCKED_PAGE)
 906                 f2fs_put_page(apage, 1);
 907         return;
 908 }
 909
 910 struct page *get_node_page(struct f2fs_sb_info *sbi, pgoff_t nid)
 911 {
 912         struct address_space *mapping = sbi->node_inode->i_mapping;
 913         struct page *page;
 914         int err;
 915
 916         page = grab_cache_page(mapping, nid);
 917         if (!page)
 918                 return ERR_PTR(-ENOMEM);
 919
 920         err = read_node_page(page, READ_SYNC);
 921         if (err < 0)
 922                 return ERR_PTR(err);
 923         else if (err == LOCKED_PAGE)
 924                 goto got_it;
 925
 926         lock_page(page);
 927         if (!PageUptodate(page)) {
 928                 f2fs_put_page(page, 1);
 929                 return ERR_PTR(-EIO);
 930         }
 931 got_it:
 932         BUG_ON(nid != nid_of_node(page));
 933         mark_page_accessed(page);
 934         return page;
 935 }
 936
 937 /*
 938  * Return a locked page for the desired node page.
 939  * And, readahead MAX_RA_NODE number of node pages.
 940  */
 941 struct page *get_node_page_ra(struct page *parent, int start)
 942 {
 943         struct f2fs_sb_info *sbi = F2FS_SB(parent->mapping->host->i_sb);
 944         struct address_space *mapping = sbi->node_inode->i_mapping;
 945         struct page *page;
 946         int err, i, end;
 947         nid_t nid;
 948
 949         /* First, try getting the desired direct node. */
 950         nid = get_nid(parent, start, false);
 951         if (!nid)
 952                 return ERR_PTR(-ENOENT);
 953
 954         page = grab_cache_page(mapping, nid);
 955         if (!page)
 956                 return ERR_PTR(-ENOMEM);
 957
 958         err = read_node_page(page, READ_SYNC);
 959         if (err < 0)
 960                 return ERR_PTR(err);
 961         else if (err == LOCKED_PAGE)
 962                 goto page_hit;
 963
 964         /* Then, try readahead for siblings of the desired node */
 965         end = start + MAX_RA_NODE;
 966         end = min(end, NIDS_PER_BLOCK);
 967         for (i = start + 1; i < end; i++) {
 968                 nid = get_nid(parent, i, false);
 969                 if (!nid)
 970                         continue;
 971                 ra_node_page(sbi, nid);
 972         }
 973
 974         lock_page(page);
 975
 976 page_hit:
 977         if (!PageUptodate(page)) {
 978                 f2fs_put_page(page, 1);
 979                 return ERR_PTR(-EIO);
 980         }
 981         mark_page_accessed(page);
 982         return page;
 983 }
 984
 985 void sync_inode_page(struct dnode_of_data *dn)
 986 {
 987         if (IS_INODE(dn->node_page) || dn->inode_page == dn->node_page) {
 988                 update_inode(dn->inode, dn->node_page);
 989         } else if (dn->inode_page) {
 990                 if (!dn->inode_page_locked)
 991                         lock_page(dn->inode_page);
 992                 update_inode(dn->inode, dn->inode_page);
 993                 if (!dn->inode_page_locked)
 994                         unlock_page(dn->inode_page);
 995         } else {
 996                 update_inode_page(dn->inode);
 997         }
 998 }
 999
1000 int sync_node_pages(struct f2fs_sb_info *sbi, nid_t ino,
1001                                         struct writeback_control *wbc)
1002 {
1003         struct address_space *mapping = sbi->node_inode->i_mapping;
1004         pgoff_t index, end;
1005         struct pagevec pvec;
1006         int step = ino ? 2 : 0;
1007         int nwritten = 0, wrote = 0;
1008
1009         pagevec_init(&pvec, 0);
1010
1011 next_step:
1012         index = 0;
1013         end = LONG_MAX;
1014
1015         while (index <= end) {
1016                 int i, nr_pages;
1017                 nr_pages = pagevec_lookup_tag(&pvec, mapping, &index,
1018                                 PAGECACHE_TAG_DIRTY,
1019                                 min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1);
1020                 if (nr_pages == 0)
1021                         break;
1022
1023                 for (i = 0; i < nr_pages; i++) {
1024                         struct page *page = pvec.pages[i];
1025
1026                         /*
1027                          * flushing sequence with step:
1028                          * 0. indirect nodes
1029                          * 1. dentry dnodes
1030                          * 2. file dnodes
1031                          */
1032                         if (step == 0 && IS_DNODE(page))
1033                                 continue;
1034                         if (step == 1 && (!IS_DNODE(page) ||
1035                                                 is_cold_node(page)))
1036                                 continue;
1037                         if (step == 2 && (!IS_DNODE(page) ||
1038                                                 !is_cold_node(page)))
1039                                 continue;
1040
1041                         /*
1042                          * If an fsync mode,
1043                          * we should not skip writing node pages.
1044                          */
1045                         if (ino && ino_of_node(page) == ino)
1046                                 lock_page(page);
1047                         else if (!trylock_page(page))
1048                                 continue;
1049
1050                         if (unlikely(page->mapping != mapping)) {
1051 continue_unlock:
1052                                 unlock_page(page);
1053                                 continue;
1054                         }
1055                         if (ino && ino_of_node(page) != ino)
1056                                 goto continue_unlock;
1057
1058                         if (!PageDirty(page)) {
1059                                 /* someone wrote it for us */
1060                                 goto continue_unlock;
1061                         }
1062
1063                         if (!clear_page_dirty_for_io(page))
1064                                 goto continue_unlock;
1065
1066                         /* called by fsync() */
1067                         if (ino && IS_DNODE(page)) {
1068                                 int mark = !is_checkpointed_node(sbi, ino);
1069                                 set_fsync_mark(page, 1);
1070                                 if (IS_INODE(page))
1071                                         set_dentry_mark(page, mark);
1072                                 nwritten++;
1073                         } else {
1074                                 set_fsync_mark(page, 0);
1075                                 set_dentry_mark(page, 0);
1076                         }
1077                         mapping->a_ops->writepage(page, wbc);
1078                         wrote++;
1079
1080                         if (--wbc->nr_to_write == 0)
1081                                 break;
1082                 }
1083                 pagevec_release(&pvec);
1084                 cond_resched();
1085
1086                 if (wbc->nr_to_write == 0) {
1087                         step = 2;
1088                         break;
1089                 }
1090         }
1091
1092         if (step < 2) {
1093                 step++;
1094                 goto next_step;
1095         }
1096
1097         if (wrote)
1098                 f2fs_submit_bio(sbi, NODE, wbc->sync_mode == WB_SYNC_ALL);
1099
1100         return nwritten;
1101 }
1102
1103 static int f2fs_write_node_page(struct page *page,
1104                                 struct writeback_control *wbc)
1105 {
1106         struct f2fs_sb_info *sbi = F2FS_SB(page->mapping->host->i_sb);
1107         nid_t nid;
1108         block_t new_addr;
1109         struct node_info ni;
1110
1111         wait_on_page_writeback(page);
1112
1113         /* get old block addr of this node page */
1114         nid = nid_of_node(page);
1115         BUG_ON(page->index != nid);
1116
1117         get_node_info(sbi, nid, &ni);
1118
1119         /* This page is already truncated */
1120         if (ni.blk_addr == NULL_ADDR) {
1121                 dec_page_count(sbi, F2FS_DIRTY_NODES);
1122                 unlock_page(page);
1123                 return 0;
1124         }
1125
1126         if (wbc->for_reclaim) {
1127                 dec_page_count(sbi, F2FS_DIRTY_NODES);
1128                 wbc->pages_skipped++;
1129                 set_page_dirty(page);
1130                 return AOP_WRITEPAGE_ACTIVATE;
1131         }
1132
1133         mutex_lock(&sbi->node_write);
1134         set_page_writeback(page);
1135         write_node_page(sbi, page, nid, ni.blk_addr, &new_addr);
1136         set_node_addr(sbi, &ni, new_addr);
1137         dec_page_count(sbi, F2FS_DIRTY_NODES);
1138         mutex_unlock(&sbi->node_write);
1139         unlock_page(page);
1140         return 0;
1141 }
1142
1143 /*
1144  * It is very important to gather dirty pages and write at once, so that we can
1145  * submit a big bio without interfering other data writes.
1146  * Be default, 512 pages (2MB), a segment size, is quite reasonable.
1147  */
1148 #define COLLECT_DIRTY_NODES     512
1149 static int f2fs_write_node_pages(struct address_space *mapping,
1150                             struct writeback_control *wbc)
1151 {
1152         struct f2fs_sb_info *sbi = F2FS_SB(mapping->host->i_sb);
1153         struct block_device *bdev = sbi->sb->s_bdev;
1154         long nr_to_write = wbc->nr_to_write;
1155
1156         /* First check balancing cached NAT entries */
1157         if (try_to_free_nats(sbi, NAT_ENTRY_PER_BLOCK)) {
1158                 f2fs_sync_fs(sbi->sb, true);
1159                 return 0;
1160         }
1161
1162         /* collect a number of dirty node pages and write together */
1163         if (get_pages(sbi, F2FS_DIRTY_NODES) < COLLECT_DIRTY_NODES)
1164                 return 0;
1165
1166         /* if mounting is failed, skip writing node pages */
1167         wbc->nr_to_write = bio_get_nr_vecs(bdev);
1168         sync_node_pages(sbi, 0, wbc);
1169         wbc->nr_to_write = nr_to_write -
1170                 (bio_get_nr_vecs(bdev) - wbc->nr_to_write);
1171         return 0;
1172 }
1173
1174 static int f2fs_set_node_page_dirty(struct page *page)
1175 {
1176         struct address_space *mapping = page->mapping;
1177         struct f2fs_sb_info *sbi = F2FS_SB(mapping->host->i_sb);
1178
1179         SetPageUptodate(page);
1180         if (!PageDirty(page)) {
1181                 __set_page_dirty_nobuffers(page);
1182                 inc_page_count(sbi, F2FS_DIRTY_NODES);
1183                 SetPagePrivate(page);
1184                 return 1;
1185         }
1186         return 0;
1187 }
1188
1189 static void f2fs_invalidate_node_page(struct page *page, unsigned long offset)
1190 {
1191         struct inode *inode = page->mapping->host;
1192         struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
1193         if (PageDirty(page))
1194                 dec_page_count(sbi, F2FS_DIRTY_NODES);
1195         ClearPagePrivate(page);
1196 }
1197
1198 static int f2fs_release_node_page(struct page *page, gfp_t wait)
1199 {
1200         ClearPagePrivate(page);
1201         return 1;
1202 }
1203
1204 /*
1205  * Structure of the f2fs node operations
1206  */
1207 const struct address_space_operations f2fs_node_aops = {
1208         .writepage      = f2fs_write_node_page,
1209         .writepages     = f2fs_write_node_pages,
1210         .set_page_dirty = f2fs_set_node_page_dirty,
1211         .invalidatepage = f2fs_invalidate_node_page,
1212         .releasepage    = f2fs_release_node_page,
1213 };
1214
1215 static struct free_nid *__lookup_free_nid_list(nid_t n, struct list_head *head)
1216 {
1217         struct list_head *this;
1218         struct free_nid *i;
1219         list_for_each(this, head) {
1220                 i = list_entry(this, struct free_nid, list);
1221                 if (i->nid == n)
1222                         return i;
1223         }
1224         return NULL;
1225 }
1226
1227 static void __del_from_free_nid_list(struct free_nid *i)
1228 {
1229         list_del(&i->list);
1230         kmem_cache_free(free_nid_slab, i);
1231 }
1232
1233 static int add_free_nid(struct f2fs_nm_info *nm_i, nid_t nid)
1234 {
1235         struct free_nid *i;
1236
1237         if (nm_i->fcnt > 2 * MAX_FREE_NIDS)
1238                 return 0;
1239 retry:
1240         i = kmem_cache_alloc(free_nid_slab, GFP_NOFS);
1241         if (!i) {
1242                 cond_resched();
1243                 goto retry;
1244         }
1245         i->nid = nid;
1246         i->state = NID_NEW;
1247
1248         spin_lock(&nm_i->free_nid_list_lock);
1249         if (__lookup_free_nid_list(nid, &nm_i->free_nid_list)) {
1250                 spin_unlock(&nm_i->free_nid_list_lock);
1251                 kmem_cache_free(free_nid_slab, i);
1252                 return 0;
1253         }
1254         list_add_tail(&i->list, &nm_i->free_nid_list);
1255         nm_i->fcnt++;
1256         spin_unlock(&nm_i->free_nid_list_lock);
1257         return 1;
1258 }
1259
1260 static void remove_free_nid(struct f2fs_nm_info *nm_i, nid_t nid)
1261 {
1262         struct free_nid *i;
1263         spin_lock(&nm_i->free_nid_list_lock);
1264         i = __lookup_free_nid_list(nid, &nm_i->free_nid_list);
1265         if (i && i->state == NID_NEW) {
1266                 __del_from_free_nid_list(i);
1267                 nm_i->fcnt--;
1268         }
1269         spin_unlock(&nm_i->free_nid_list_lock);
1270 }
1271
1272 static int scan_nat_page(struct f2fs_nm_info *nm_i,
1273                         struct page *nat_page, nid_t start_nid)
1274 {
1275         struct f2fs_nat_block *nat_blk = page_address(nat_page);
1276         block_t blk_addr;
1277         int fcnt = 0;
1278         int i;
1279
1280         /* 0 nid should not be used */
1281         if (start_nid == 0)
1282                 ++start_nid;
1283
1284         i = start_nid % NAT_ENTRY_PER_BLOCK;
1285
1286         for (; i < NAT_ENTRY_PER_BLOCK; i++, start_nid++) {
1287                 if (start_nid >= nm_i->max_nid)
1288                         break;
1289                 blk_addr  = le32_to_cpu(nat_blk->entries[i].block_addr);
1290                 BUG_ON(blk_addr == NEW_ADDR);
1291                 if (blk_addr == NULL_ADDR)
1292                         fcnt += add_free_nid(nm_i, start_nid);
1293         }
1294         return fcnt;
1295 }
1296
1297 static void build_free_nids(struct f2fs_sb_info *sbi)
1298 {
1299         struct free_nid *fnid, *next_fnid;
1300         struct f2fs_nm_info *nm_i = NM_I(sbi);
1301         struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_HOT_DATA);
1302         struct f2fs_summary_block *sum = curseg->sum_blk;
1303         nid_t nid = 0;
1304         bool is_cycled = false;
1305         int fcnt = 0;
1306         int i;
1307
1308         nid = nm_i->next_scan_nid;
1309         nm_i->init_scan_nid = nid;
1310
1311         ra_nat_pages(sbi, nid);
1312
1313         while (1) {
1314                 struct page *page = get_current_nat_page(sbi, nid);
1315
1316                 fcnt += scan_nat_page(nm_i, page, nid);
1317                 f2fs_put_page(page, 1);
1318
1319                 nid += (NAT_ENTRY_PER_BLOCK - (nid % NAT_ENTRY_PER_BLOCK));
1320
1321                 if (nid >= nm_i->max_nid) {
1322                         nid = 0;
1323                         is_cycled = true;
1324                 }
1325                 if (fcnt > MAX_FREE_NIDS)
1326                         break;
1327                 if (is_cycled && nm_i->init_scan_nid <= nid)
1328                         break;
1329         }
1330
1331         /* go to the next nat page in order to reuse free nids first */
1332         nm_i->next_scan_nid = nm_i->init_scan_nid + NAT_ENTRY_PER_BLOCK;
1333
1334         /* find free nids from current sum_pages */
1335         mutex_lock(&curseg->curseg_mutex);
1336         for (i = 0; i < nats_in_cursum(sum); i++) {
1337                 block_t addr = le32_to_cpu(nat_in_journal(sum, i).block_addr);
1338                 nid = le32_to_cpu(nid_in_journal(sum, i));
1339                 if (addr == NULL_ADDR)
1340                         add_free_nid(nm_i, nid);
1341                 else
1342                         remove_free_nid(nm_i, nid);
1343         }
1344         mutex_unlock(&curseg->curseg_mutex);
1345
1346         /* remove the free nids from current allocated nids */
1347         list_for_each_entry_safe(fnid, next_fnid, &nm_i->free_nid_list, list) {
1348                 struct nat_entry *ne;
1349
1350                 read_lock(&nm_i->nat_tree_lock);
1351                 ne = __lookup_nat_cache(nm_i, fnid->nid);
1352                 if (ne && nat_get_blkaddr(ne) != NULL_ADDR)
1353                         remove_free_nid(nm_i, fnid->nid);
1354                 read_unlock(&nm_i->nat_tree_lock);
1355         }
1356 }
1357
1358 /*
1359  * If this function returns success, caller can obtain a new nid
1360  * from second parameter of this function.
1361  * The returned nid could be used ino as well as nid when inode is created.
1362  */
1363 bool alloc_nid(struct f2fs_sb_info *sbi, nid_t *nid)
1364 {
1365         struct f2fs_nm_info *nm_i = NM_I(sbi);
1366         struct free_nid *i = NULL;
1367         struct list_head *this;
1368 retry:
1369         mutex_lock(&nm_i->build_lock);
1370         if (!nm_i->fcnt) {
1371                 /* scan NAT in order to build free nid list */
1372                 build_free_nids(sbi);
1373                 if (!nm_i->fcnt) {
1374                         mutex_unlock(&nm_i->build_lock);
1375                         return false;
1376                 }
1377         }
1378         mutex_unlock(&nm_i->build_lock);
1379
1380         /*
1381          * We check fcnt again since previous check is racy as
1382          * we didn't hold free_nid_list_lock. So other thread
1383          * could consume all of free nids.
1384          */
1385         spin_lock(&nm_i->free_nid_list_lock);
1386         if (!nm_i->fcnt) {
1387                 spin_unlock(&nm_i->free_nid_list_lock);
1388                 goto retry;
1389         }
1390
1391         BUG_ON(list_empty(&nm_i->free_nid_list));
1392         list_for_each(this, &nm_i->free_nid_list) {
1393                 i = list_entry(this, struct free_nid, list);
1394                 if (i->state == NID_NEW)
1395                         break;
1396         }
1397
1398         BUG_ON(i->state != NID_NEW);
1399         *nid = i->nid;
1400         i->state = NID_ALLOC;
1401         nm_i->fcnt--;
1402         spin_unlock(&nm_i->free_nid_list_lock);
1403         return true;
1404 }
1405
1406 /*
1407  * alloc_nid() should be called prior to this function.
1408  */
1409 void alloc_nid_done(struct f2fs_sb_info *sbi, nid_t nid)
1410 {
1411         struct f2fs_nm_info *nm_i = NM_I(sbi);
1412         struct free_nid *i;
1413
1414         spin_lock(&nm_i->free_nid_list_lock);
1415         i = __lookup_free_nid_list(nid, &nm_i->free_nid_list);
1416         BUG_ON(!i || i->state != NID_ALLOC);
1417         __del_from_free_nid_list(i);
1418         spin_unlock(&nm_i->free_nid_list_lock);
1419 }
1420
1421 /*
1422  * alloc_nid() should be called prior to this function.
1423  */
1424 void alloc_nid_failed(struct f2fs_sb_info *sbi, nid_t nid)
1425 {
1426         struct f2fs_nm_info *nm_i = NM_I(sbi);
1427         struct free_nid *i;
1428
1429         spin_lock(&nm_i->free_nid_list_lock);
1430         i = __lookup_free_nid_list(nid, &nm_i->free_nid_list);
1431         BUG_ON(!i || i->state != NID_ALLOC);
1432         i->state = NID_NEW;
1433         nm_i->fcnt++;
1434         spin_unlock(&nm_i->free_nid_list_lock);
1435 }
1436
1437 void recover_node_page(struct f2fs_sb_info *sbi, struct page *page,
1438                 struct f2fs_summary *sum, struct node_info *ni,
1439                 block_t new_blkaddr)
1440 {
1441         rewrite_node_page(sbi, page, sum, ni->blk_addr, new_blkaddr);
1442         set_node_addr(sbi, ni, new_blkaddr);
1443         clear_node_page_dirty(page);
1444 }
1445
1446 int recover_inode_page(struct f2fs_sb_info *sbi, struct page *page)
1447 {
1448         struct address_space *mapping = sbi->node_inode->i_mapping;
1449         struct f2fs_node *src, *dst;
1450         nid_t ino = ino_of_node(page);
1451         struct node_info old_ni, new_ni;
1452         struct page *ipage;
1453
1454         ipage = grab_cache_page(mapping, ino);
1455         if (!ipage)
1456                 return -ENOMEM;
1457
1458         /* Should not use this inode  from free nid list */
1459         remove_free_nid(NM_I(sbi), ino);
1460
1461         get_node_info(sbi, ino, &old_ni);
1462         SetPageUptodate(ipage);
1463         fill_node_footer(ipage, ino, ino, 0, true);
1464
1465         src = (struct f2fs_node *)page_address(page);
1466         dst = (struct f2fs_node *)page_address(ipage);
1467
1468         memcpy(dst, src, (unsigned long)&src->i.i_ext - (unsigned long)&src->i);
1469         dst->i.i_size = 0;
1470         dst->i.i_blocks = cpu_to_le64(1);
1471         dst->i.i_links = cpu_to_le32(1);
1472         dst->i.i_xattr_nid = 0;
1473
1474         new_ni = old_ni;
1475         new_ni.ino = ino;
1476
1477         set_node_addr(sbi, &new_ni, NEW_ADDR);
1478         inc_valid_inode_count(sbi);
1479
1480         f2fs_put_page(ipage, 1);
1481         return 0;
1482 }
1483
1484 int restore_node_summary(struct f2fs_sb_info *sbi,
1485                         unsigned int segno, struct f2fs_summary_block *sum)
1486 {
1487         struct f2fs_node *rn;
1488         struct f2fs_summary *sum_entry;
1489         struct page *page;
1490         block_t addr;
1491         int i, last_offset;
1492
1493         /* alloc temporal page for read node */
1494         page = alloc_page(GFP_NOFS | __GFP_ZERO);
1495         if (IS_ERR(page))
1496                 return PTR_ERR(page);
1497         lock_page(page);
1498
1499         /* scan the node segment */
1500         last_offset = sbi->blocks_per_seg;
1501         addr = START_BLOCK(sbi, segno);
1502         sum_entry = &sum->entries[0];
1503
1504         for (i = 0; i < last_offset; i++, sum_entry++) {
1505                 /*
1506                  * In order to read next node page,
1507                  * we must clear PageUptodate flag.
1508                  */
1509                 ClearPageUptodate(page);
1510
1511                 if (f2fs_readpage(sbi, page, addr, READ_SYNC))
1512                         goto out;
1513
1514                 lock_page(page);
1515                 rn = (struct f2fs_node *)page_address(page);
1516                 sum_entry->nid = rn->footer.nid;
1517                 sum_entry->version = 0;
1518                 sum_entry->ofs_in_node = 0;
1519                 addr++;
1520         }
1521         unlock_page(page);
1522 out:
1523         __free_pages(page, 0);
1524         return 0;
1525 }
1526
1527 static bool flush_nats_in_journal(struct f2fs_sb_info *sbi)
1528 {
1529         struct f2fs_nm_info *nm_i = NM_I(sbi);
1530         struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_HOT_DATA);
1531         struct f2fs_summary_block *sum = curseg->sum_blk;
1532         int i;
1533
1534         mutex_lock(&curseg->curseg_mutex);
1535
1536         if (nats_in_cursum(sum) < NAT_JOURNAL_ENTRIES) {
1537                 mutex_unlock(&curseg->curseg_mutex);
1538                 return false;
1539         }
1540
1541         for (i = 0; i < nats_in_cursum(sum); i++) {
1542                 struct nat_entry *ne;
1543                 struct f2fs_nat_entry raw_ne;
1544                 nid_t nid = le32_to_cpu(nid_in_journal(sum, i));
1545
1546                 raw_ne = nat_in_journal(sum, i);
1547 retry:
1548                 write_lock(&nm_i->nat_tree_lock);
1549                 ne = __lookup_nat_cache(nm_i, nid);
1550                 if (ne) {
1551                         __set_nat_cache_dirty(nm_i, ne);
1552                         write_unlock(&nm_i->nat_tree_lock);
1553                         continue;
1554                 }
1555                 ne = grab_nat_entry(nm_i, nid);
1556                 if (!ne) {
1557                         write_unlock(&nm_i->nat_tree_lock);
1558                         goto retry;
1559                 }
1560                 nat_set_blkaddr(ne, le32_to_cpu(raw_ne.block_addr));
1561                 nat_set_ino(ne, le32_to_cpu(raw_ne.ino));
1562                 nat_set_version(ne, raw_ne.version);
1563                 __set_nat_cache_dirty(nm_i, ne);
1564                 write_unlock(&nm_i->nat_tree_lock);
1565         }
1566         update_nats_in_cursum(sum, -i);
1567         mutex_unlock(&curseg->curseg_mutex);
1568         return true;
1569 }
1570
1571 /*
1572  * This function is called during the checkpointing process.
1573  */
1574 void flush_nat_entries(struct f2fs_sb_info *sbi)
1575 {
1576         struct f2fs_nm_info *nm_i = NM_I(sbi);
1577         struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_HOT_DATA);
1578         struct f2fs_summary_block *sum = curseg->sum_blk;
1579         struct list_head *cur, *n;
1580         struct page *page = NULL;
1581         struct f2fs_nat_block *nat_blk = NULL;
1582         nid_t start_nid = 0, end_nid = 0;
1583         bool flushed;
1584
1585         flushed = flush_nats_in_journal(sbi);
1586
1587         if (!flushed)
1588                 mutex_lock(&curseg->curseg_mutex);
1589
1590         /* 1) flush dirty nat caches */
1591         list_for_each_safe(cur, n, &nm_i->dirty_nat_entries) {
1592                 struct nat_entry *ne;
1593                 nid_t nid;
1594                 struct f2fs_nat_entry raw_ne;
1595                 int offset = -1;
1596                 block_t new_blkaddr;
1597
1598                 ne = list_entry(cur, struct nat_entry, list);
1599                 nid = nat_get_nid(ne);
1600
1601                 if (nat_get_blkaddr(ne) == NEW_ADDR)
1602                         continue;
1603                 if (flushed)
1604                         goto to_nat_page;
1605
1606                 /* if there is room for nat enries in curseg->sumpage */
1607                 offset = lookup_journal_in_cursum(sum, NAT_JOURNAL, nid, 1);
1608                 if (offset >= 0) {
1609                         raw_ne = nat_in_journal(sum, offset);
1610                         goto flush_now;
1611                 }
1612 to_nat_page:
1613                 if (!page || (start_nid > nid || nid > end_nid)) {
1614                         if (page) {
1615                                 f2fs_put_page(page, 1);
1616                                 page = NULL;
1617                         }
1618                         start_nid = START_NID(nid);
1619                         end_nid = start_nid + NAT_ENTRY_PER_BLOCK - 1;
1620
1621                         /*
1622                          * get nat block with dirty flag, increased reference
1623                          * count, mapped and lock
1624                          */
1625                         page = get_next_nat_page(sbi, start_nid);
1626                         nat_blk = page_address(page);
1627                 }
1628
1629                 BUG_ON(!nat_blk);
1630                 raw_ne = nat_blk->entries[nid - start_nid];
1631 flush_now:
1632                 new_blkaddr = nat_get_blkaddr(ne);
1633
1634                 raw_ne.ino = cpu_to_le32(nat_get_ino(ne));
1635                 raw_ne.block_addr = cpu_to_le32(new_blkaddr);
1636                 raw_ne.version = nat_get_version(ne);
1637
1638                 if (offset < 0) {
1639                         nat_blk->entries[nid - start_nid] = raw_ne;
1640                 } else {
1641                         nat_in_journal(sum, offset) = raw_ne;
1642                         nid_in_journal(sum, offset) = cpu_to_le32(nid);
1643                 }
1644
1645                 if (nat_get_blkaddr(ne) == NULL_ADDR &&
1646                                         !add_free_nid(NM_I(sbi), nid)) {
1647                         write_lock(&nm_i->nat_tree_lock);
1648                         __del_from_nat_cache(nm_i, ne);
1649                         write_unlock(&nm_i->nat_tree_lock);
1650                 } else {
1651                         write_lock(&nm_i->nat_tree_lock);
1652                         __clear_nat_cache_dirty(nm_i, ne);
1653                         ne->checkpointed = true;
1654                         write_unlock(&nm_i->nat_tree_lock);
1655                 }
1656         }
1657         if (!flushed)
1658                 mutex_unlock(&curseg->curseg_mutex);
1659         f2fs_put_page(page, 1);
1660
1661         /* 2) shrink nat caches if necessary */
1662         try_to_free_nats(sbi, nm_i->nat_cnt - NM_WOUT_THRESHOLD);
1663 }
1664
1665 static int init_node_manager(struct f2fs_sb_info *sbi)
1666 {
1667         struct f2fs_super_block *sb_raw = F2FS_RAW_SUPER(sbi);
1668         struct f2fs_nm_info *nm_i = NM_I(sbi);
1669         unsigned char *version_bitmap;
1670         unsigned int nat_segs, nat_blocks;
1671
1672         nm_i->nat_blkaddr = le32_to_cpu(sb_raw->nat_blkaddr);
1673
1674         /* segment_count_nat includes pair segment so divide to 2. */
1675         nat_segs = le32_to_cpu(sb_raw->segment_count_nat) >> 1;
1676         nat_blocks = nat_segs << le32_to_cpu(sb_raw->log_blocks_per_seg);
1677         nm_i->max_nid = NAT_ENTRY_PER_BLOCK * nat_blocks;
1678         nm_i->fcnt = 0;
1679         nm_i->nat_cnt = 0;
1680
1681         INIT_LIST_HEAD(&nm_i->free_nid_list);
1682         INIT_RADIX_TREE(&nm_i->nat_root, GFP_ATOMIC);
1683         INIT_LIST_HEAD(&nm_i->nat_entries);
1684         INIT_LIST_HEAD(&nm_i->dirty_nat_entries);
1685
1686         mutex_init(&nm_i->build_lock);
1687         spin_lock_init(&nm_i->free_nid_list_lock);
1688         rwlock_init(&nm_i->nat_tree_lock);
1689
1690         nm_i->init_scan_nid = le32_to_cpu(sbi->ckpt->next_free_nid);
1691         nm_i->next_scan_nid = le32_to_cpu(sbi->ckpt->next_free_nid);
1692         nm_i->bitmap_size = __bitmap_size(sbi, NAT_BITMAP);
1693         version_bitmap = __bitmap_ptr(sbi, NAT_BITMAP);
1694         if (!version_bitmap)
1695                 return -EFAULT;
1696
1697         nm_i->nat_bitmap = kmemdup(version_bitmap, nm_i->bitmap_size,
1698                                         GFP_KERNEL);
1699         if (!nm_i->nat_bitmap)
1700                 return -ENOMEM;
1701         return 0;
1702 }
1703
1704 int build_node_manager(struct f2fs_sb_info *sbi)
1705 {
1706         int err;
1707
1708         sbi->nm_info = kzalloc(sizeof(struct f2fs_nm_info), GFP_KERNEL);
1709         if (!sbi->nm_info)
1710                 return -ENOMEM;
1711
1712         err = init_node_manager(sbi);
1713         if (err)
1714                 return err;
1715
1716         build_free_nids(sbi);
1717         return 0;
1718 }
1719
1720 void destroy_node_manager(struct f2fs_sb_info *sbi)
1721 {
1722         struct f2fs_nm_info *nm_i = NM_I(sbi);
1723         struct free_nid *i, *next_i;
1724         struct nat_entry *natvec[NATVEC_SIZE];
1725         nid_t nid = 0;
1726         unsigned int found;
1727
1728         if (!nm_i)
1729                 return;
1730
1731         /* destroy free nid list */
1732         spin_lock(&nm_i->free_nid_list_lock);
1733         list_for_each_entry_safe(i, next_i, &nm_i->free_nid_list, list) {
1734                 BUG_ON(i->state == NID_ALLOC);
1735                 __del_from_free_nid_list(i);
1736                 nm_i->fcnt--;
1737         }
1738         BUG_ON(nm_i->fcnt);
1739         spin_unlock(&nm_i->free_nid_list_lock);
1740
1741         /* destroy nat cache */
1742         write_lock(&nm_i->nat_tree_lock);
1743         while ((found = __gang_lookup_nat_cache(nm_i,
1744                                         nid, NATVEC_SIZE, natvec))) {
1745                 unsigned idx;
1746                 for (idx = 0; idx < found; idx++) {
1747                         struct nat_entry *e = natvec[idx];
1748                         nid = nat_get_nid(e) + 1;
1749                         __del_from_nat_cache(nm_i, e);
1750                 }
1751         }
1752         BUG_ON(nm_i->nat_cnt);
1753         write_unlock(&nm_i->nat_tree_lock);
1754
1755         kfree(nm_i->nat_bitmap);
1756         sbi->nm_info = NULL;
1757         kfree(nm_i);
1758 }
1759
1760 int __init create_node_manager_caches(void)
1761 {
1762         nat_entry_slab = f2fs_kmem_cache_create("nat_entry",
1763                         sizeof(struct nat_entry), NULL);
1764         if (!nat_entry_slab)
1765                 return -ENOMEM;
1766
1767         free_nid_slab = f2fs_kmem_cache_create("free_nid",
1768                         sizeof(struct free_nid), NULL);
1769         if (!free_nid_slab) {
1770                 kmem_cache_destroy(nat_entry_slab);
1771                 return -ENOMEM;
1772         }
1773         return 0;
1774 }
1775
1776 void destroy_node_manager_caches(void)
1777 {
1778         kmem_cache_destroy(free_nid_slab);
1779         kmem_cache_destroy(nat_entry_slab);
1780 }