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 blk_plug plug;
  93         struct page *page;
  94         pgoff_t index;
  95         int i;
  96
  97         blk_start_plug(&plug);
  98
  99         for (i = 0; i < FREE_NID_PAGES; i++, nid += NAT_ENTRY_PER_BLOCK) {
 100                 if (nid >= nm_i->max_nid)
 101                         nid = 0;
 102                 index = current_nat_addr(sbi, nid);
 103
 104                 page = grab_cache_page(mapping, index);
 105                 if (!page)
 106                         continue;
 107                 if (PageUptodate(page)) {
 108                         f2fs_put_page(page, 1);
 109                         continue;
 110                 }
 111                 if (f2fs_readpage(sbi, page, index, READ))
 112                         continue;
 113
 114                 f2fs_put_page(page, 0);
 115         }
 116         blk_finish_plug(&plug);
 117 }
 118
 119 static struct nat_entry *__lookup_nat_cache(struct f2fs_nm_info *nm_i, nid_t n)
 120 {
 121         return radix_tree_lookup(&nm_i->nat_root, n);
 122 }
 123
 124 static unsigned int __gang_lookup_nat_cache(struct f2fs_nm_info *nm_i,
 125                 nid_t start, unsigned int nr, struct nat_entry **ep)
 126 {
 127         return radix_tree_gang_lookup(&nm_i->nat_root, (void **)ep, start, nr);
 128 }
 129
 130 static void __del_from_nat_cache(struct f2fs_nm_info *nm_i, struct nat_entry *e)
 131 {
 132         list_del(&e->list);
 133         radix_tree_delete(&nm_i->nat_root, nat_get_nid(e));
 134         nm_i->nat_cnt--;
 135         kmem_cache_free(nat_entry_slab, e);
 136 }
 137
 138 int is_checkpointed_node(struct f2fs_sb_info *sbi, nid_t nid)
 139 {
 140         struct f2fs_nm_info *nm_i = NM_I(sbi);
 141         struct nat_entry *e;
 142         int is_cp = 1;
 143
 144         read_lock(&nm_i->nat_tree_lock);
 145         e = __lookup_nat_cache(nm_i, nid);
 146         if (e && !e->checkpointed)
 147                 is_cp = 0;
 148         read_unlock(&nm_i->nat_tree_lock);
 149         return is_cp;
 150 }
 151
 152 static struct nat_entry *grab_nat_entry(struct f2fs_nm_info *nm_i, nid_t nid)
 153 {
 154         struct nat_entry *new;
 155
 156         new = kmem_cache_alloc(nat_entry_slab, GFP_ATOMIC);
 157         if (!new)
 158                 return NULL;
 159         if (radix_tree_insert(&nm_i->nat_root, nid, new)) {
 160                 kmem_cache_free(nat_entry_slab, new);
 161                 return NULL;
 162         }
 163         memset(new, 0, sizeof(struct nat_entry));
 164         nat_set_nid(new, nid);
 165         list_add_tail(&new->list, &nm_i->nat_entries);
 166         nm_i->nat_cnt++;
 167         return new;
 168 }
 169
 170 static void cache_nat_entry(struct f2fs_nm_info *nm_i, nid_t nid,
 171                                                 struct f2fs_nat_entry *ne)
 172 {
 173         struct nat_entry *e;
 174 retry:
 175         write_lock(&nm_i->nat_tree_lock);
 176         e = __lookup_nat_cache(nm_i, nid);
 177         if (!e) {
 178                 e = grab_nat_entry(nm_i, nid);
 179                 if (!e) {
 180                         write_unlock(&nm_i->nat_tree_lock);
 181                         goto retry;
 182                 }
 183                 nat_set_blkaddr(e, le32_to_cpu(ne->block_addr));
 184                 nat_set_ino(e, le32_to_cpu(ne->ino));
 185                 nat_set_version(e, ne->version);
 186                 e->checkpointed = true;
 187         }
 188         write_unlock(&nm_i->nat_tree_lock);
 189 }
 190
 191 static void set_node_addr(struct f2fs_sb_info *sbi, struct node_info *ni,
 192                         block_t new_blkaddr)
 193 {
 194         struct f2fs_nm_info *nm_i = NM_I(sbi);
 195         struct nat_entry *e;
 196 retry:
 197         write_lock(&nm_i->nat_tree_lock);
 198         e = __lookup_nat_cache(nm_i, ni->nid);
 199         if (!e) {
 200                 e = grab_nat_entry(nm_i, ni->nid);
 201                 if (!e) {
 202                         write_unlock(&nm_i->nat_tree_lock);
 203                         goto retry;
 204                 }
 205                 e->ni = *ni;
 206                 e->checkpointed = true;
 207                 BUG_ON(ni->blk_addr == NEW_ADDR);
 208         } else if (new_blkaddr == NEW_ADDR) {
 209                 /*
 210                  * when nid is reallocated,
 211                  * previous nat entry can be remained in nat cache.
 212                  * So, reinitialize it with new information.
 213                  */
 214                 e->ni = *ni;
 215                 BUG_ON(ni->blk_addr != NULL_ADDR);
 216         }
 217
 218         if (new_blkaddr == NEW_ADDR)
 219                 e->checkpointed = false;
 220
 221         /* sanity check */
 222         BUG_ON(nat_get_blkaddr(e) != ni->blk_addr);
 223         BUG_ON(nat_get_blkaddr(e) == NULL_ADDR &&
 224                         new_blkaddr == NULL_ADDR);
 225         BUG_ON(nat_get_blkaddr(e) == NEW_ADDR &&
 226                         new_blkaddr == NEW_ADDR);
 227         BUG_ON(nat_get_blkaddr(e) != NEW_ADDR &&
 228                         nat_get_blkaddr(e) != NULL_ADDR &&
 229                         new_blkaddr == NEW_ADDR);
 230
 231         /* increament version no as node is removed */
 232         if (nat_get_blkaddr(e) != NEW_ADDR && new_blkaddr == NULL_ADDR) {
 233                 unsigned char version = nat_get_version(e);
 234                 nat_set_version(e, inc_node_version(version));
 235         }
 236
 237         /* change address */
 238         nat_set_blkaddr(e, new_blkaddr);
 239         __set_nat_cache_dirty(nm_i, e);
 240         write_unlock(&nm_i->nat_tree_lock);
 241 }
 242
 243 static int try_to_free_nats(struct f2fs_sb_info *sbi, int nr_shrink)
 244 {
 245         struct f2fs_nm_info *nm_i = NM_I(sbi);
 246
 247         if (nm_i->nat_cnt <= NM_WOUT_THRESHOLD)
 248                 return 0;
 249
 250         write_lock(&nm_i->nat_tree_lock);
 251         while (nr_shrink && !list_empty(&nm_i->nat_entries)) {
 252                 struct nat_entry *ne;
 253                 ne = list_first_entry(&nm_i->nat_entries,
 254                                         struct nat_entry, list);
 255                 __del_from_nat_cache(nm_i, ne);
 256                 nr_shrink--;
 257         }
 258         write_unlock(&nm_i->nat_tree_lock);
 259         return nr_shrink;
 260 }
 261
 262 /*
 263  * This function returns always success
 264  */
 265 void get_node_info(struct f2fs_sb_info *sbi, nid_t nid, struct node_info *ni)
 266 {
 267         struct f2fs_nm_info *nm_i = NM_I(sbi);
 268         struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_HOT_DATA);
 269         struct f2fs_summary_block *sum = curseg->sum_blk;
 270         nid_t start_nid = START_NID(nid);
 271         struct f2fs_nat_block *nat_blk;
 272         struct page *page = NULL;
 273         struct f2fs_nat_entry ne;
 274         struct nat_entry *e;
 275         int i;
 276
 277         memset(&ne, 0, sizeof(struct f2fs_nat_entry));
 278         ni->nid = nid;
 279
 280         /* Check nat cache */
 281         read_lock(&nm_i->nat_tree_lock);
 282         e = __lookup_nat_cache(nm_i, nid);
 283         if (e) {
 284                 ni->ino = nat_get_ino(e);
 285                 ni->blk_addr = nat_get_blkaddr(e);
 286                 ni->version = nat_get_version(e);
 287         }
 288         read_unlock(&nm_i->nat_tree_lock);
 289         if (e)
 290                 return;
 291
 292         /* Check current segment summary */
 293         mutex_lock(&curseg->curseg_mutex);
 294         i = lookup_journal_in_cursum(sum, NAT_JOURNAL, nid, 0);
 295         if (i >= 0) {
 296                 ne = nat_in_journal(sum, i);
 297                 node_info_from_raw_nat(ni, &ne);
 298         }
 299         mutex_unlock(&curseg->curseg_mutex);
 300         if (i >= 0)
 301                 goto cache;
 302
 303         /* Fill node_info from nat page */
 304         page = get_current_nat_page(sbi, start_nid);
 305         nat_blk = (struct f2fs_nat_block *)page_address(page);
 306         ne = nat_blk->entries[nid - start_nid];
 307         node_info_from_raw_nat(ni, &ne);
 308         f2fs_put_page(page, 1);
 309 cache:
 310         /* cache nat entry */
 311         cache_nat_entry(NM_I(sbi), nid, &ne);
 312 }
 313
 314 /*
 315  * The maximum depth is four.
 316  * Offset[0] will have raw inode offset.
 317  */
 318 static int get_node_path(long block, int offset[4], unsigned int noffset[4])
 319 {
 320         const long direct_index = ADDRS_PER_INODE;
 321         const long direct_blks = ADDRS_PER_BLOCK;
 322         const long dptrs_per_blk = NIDS_PER_BLOCK;
 323         const long indirect_blks = ADDRS_PER_BLOCK * NIDS_PER_BLOCK;
 324         const long dindirect_blks = indirect_blks * NIDS_PER_BLOCK;
 325         int n = 0;
 326         int level = 0;
 327
 328         noffset[0] = 0;
 329
 330         if (block < direct_index) {
 331                 offset[n] = block;
 332                 goto got;
 333         }
 334         block -= direct_index;
 335         if (block < direct_blks) {
 336                 offset[n++] = NODE_DIR1_BLOCK;
 337                 noffset[n] = 1;
 338                 offset[n] = block;
 339                 level = 1;
 340                 goto got;
 341         }
 342         block -= direct_blks;
 343         if (block < direct_blks) {
 344                 offset[n++] = NODE_DIR2_BLOCK;
 345                 noffset[n] = 2;
 346                 offset[n] = block;
 347                 level = 1;
 348                 goto got;
 349         }
 350         block -= direct_blks;
 351         if (block < indirect_blks) {
 352                 offset[n++] = NODE_IND1_BLOCK;
 353                 noffset[n] = 3;
 354                 offset[n++] = block / direct_blks;
 355                 noffset[n] = 4 + offset[n - 1];
 356                 offset[n] = block % direct_blks;
 357                 level = 2;
 358                 goto got;
 359         }
 360         block -= indirect_blks;
 361         if (block < indirect_blks) {
 362                 offset[n++] = NODE_IND2_BLOCK;
 363                 noffset[n] = 4 + dptrs_per_blk;
 364                 offset[n++] = block / direct_blks;
 365                 noffset[n] = 5 + dptrs_per_blk + offset[n - 1];
 366                 offset[n] = block % direct_blks;
 367                 level = 2;
 368                 goto got;
 369         }
 370         block -= indirect_blks;
 371         if (block < dindirect_blks) {
 372                 offset[n++] = NODE_DIND_BLOCK;
 373                 noffset[n] = 5 + (dptrs_per_blk * 2);
 374                 offset[n++] = block / indirect_blks;
 375                 noffset[n] = 6 + (dptrs_per_blk * 2) +
 376                               offset[n - 1] * (dptrs_per_blk + 1);
 377                 offset[n++] = (block / direct_blks) % dptrs_per_blk;
 378                 noffset[n] = 7 + (dptrs_per_blk * 2) +
 379                               offset[n - 2] * (dptrs_per_blk + 1) +
 380                               offset[n - 1];
 381                 offset[n] = block % direct_blks;
 382                 level = 3;
 383                 goto got;
 384         } else {
 385                 BUG();
 386         }
 387 got:
 388         return level;
 389 }
 390
 391 /*
 392  * Caller should call f2fs_put_dnode(dn).
 393  * Also, it should grab and release a mutex by calling mutex_lock_op() and
 394  * mutex_unlock_op() only if ro is not set RDONLY_NODE.
 395  * In the case of RDONLY_NODE, we don't need to care about mutex.
 396  */
 397 int get_dnode_of_data(struct dnode_of_data *dn, pgoff_t index, int mode)
 398 {
 399         struct f2fs_sb_info *sbi = F2FS_SB(dn->inode->i_sb);
 400         struct page *npage[4];
 401         struct page *parent;
 402         int offset[4];
 403         unsigned int noffset[4];
 404         nid_t nids[4];
 405         int level, i;
 406         int err = 0;
 407
 408         level = get_node_path(index, offset, noffset);
 409
 410         nids[0] = dn->inode->i_ino;
 411         npage[0] = dn->inode_page;
 412
 413         if (!npage[0]) {
 414                 npage[0] = get_node_page(sbi, nids[0]);
 415                 if (IS_ERR(npage[0]))
 416                         return PTR_ERR(npage[0]);
 417         }
 418         parent = npage[0];
 419         if (level != 0)
 420                 nids[1] = get_nid(parent, offset[0], true);
 421         dn->inode_page = npage[0];
 422         dn->inode_page_locked = true;
 423
 424         /* get indirect or direct nodes */
 425         for (i = 1; i <= level; i++) {
 426                 bool done = false;
 427
 428                 if (!nids[i] && mode == ALLOC_NODE) {
 429                         /* alloc new node */
 430                         if (!alloc_nid(sbi, &(nids[i]))) {
 431                                 err = -ENOSPC;
 432                                 goto release_pages;
 433                         }
 434
 435                         dn->nid = nids[i];
 436                         npage[i] = new_node_page(dn, noffset[i], NULL);
 437                         if (IS_ERR(npage[i])) {
 438                                 alloc_nid_failed(sbi, nids[i]);
 439                                 err = PTR_ERR(npage[i]);
 440                                 goto release_pages;
 441                         }
 442
 443                         set_nid(parent, offset[i - 1], nids[i], i == 1);
 444                         alloc_nid_done(sbi, nids[i]);
 445                         done = true;
 446                 } else if (mode == LOOKUP_NODE_RA && i == level && level > 1) {
 447                         npage[i] = get_node_page_ra(parent, offset[i - 1]);
 448                         if (IS_ERR(npage[i])) {
 449                                 err = PTR_ERR(npage[i]);
 450                                 goto release_pages;
 451                         }
 452                         done = true;
 453                 }
 454                 if (i == 1) {
 455                         dn->inode_page_locked = false;
 456                         unlock_page(parent);
 457                 } else {
 458                         f2fs_put_page(parent, 1);
 459                 }
 460
 461                 if (!done) {
 462                         npage[i] = get_node_page(sbi, nids[i]);
 463                         if (IS_ERR(npage[i])) {
 464                                 err = PTR_ERR(npage[i]);
 465                                 f2fs_put_page(npage[0], 0);
 466                                 goto release_out;
 467                         }
 468                 }
 469                 if (i < level) {
 470                         parent = npage[i];
 471                         nids[i + 1] = get_nid(parent, offset[i], false);
 472                 }
 473         }
 474         dn->nid = nids[level];
 475         dn->ofs_in_node = offset[level];
 476         dn->node_page = npage[level];
 477         dn->data_blkaddr = datablock_addr(dn->node_page, dn->ofs_in_node);
 478         return 0;
 479
 480 release_pages:
 481         f2fs_put_page(parent, 1);
 482         if (i > 1)
 483                 f2fs_put_page(npage[0], 0);
 484 release_out:
 485         dn->inode_page = NULL;
 486         dn->node_page = NULL;
 487         return err;
 488 }
 489
 490 static void truncate_node(struct dnode_of_data *dn)
 491 {
 492         struct f2fs_sb_info *sbi = F2FS_SB(dn->inode->i_sb);
 493         struct node_info ni;
 494
 495         get_node_info(sbi, dn->nid, &ni);
 496         if (dn->inode->i_blocks == 0) {
 497                 BUG_ON(ni.blk_addr != NULL_ADDR);
 498                 goto invalidate;
 499         }
 500         BUG_ON(ni.blk_addr == NULL_ADDR);
 501
 502         /* Deallocate node address */
 503         invalidate_blocks(sbi, ni.blk_addr);
 504         dec_valid_node_count(sbi, dn->inode, 1);
 505         set_node_addr(sbi, &ni, NULL_ADDR);
 506
 507         if (dn->nid == dn->inode->i_ino) {
 508                 remove_orphan_inode(sbi, dn->nid);
 509                 dec_valid_inode_count(sbi);
 510         } else {
 511                 sync_inode_page(dn);
 512         }
 513 invalidate:
 514         clear_node_page_dirty(dn->node_page);
 515         F2FS_SET_SB_DIRT(sbi);
 516
 517         f2fs_put_page(dn->node_page, 1);
 518         dn->node_page = NULL;
 519         trace_f2fs_truncate_node(dn->inode, dn->nid, ni.blk_addr);
 520 }
 521
 522 static int truncate_dnode(struct dnode_of_data *dn)
 523 {
 524         struct f2fs_sb_info *sbi = F2FS_SB(dn->inode->i_sb);
 525         struct page *page;
 526
 527         if (dn->nid == 0)
 528                 return 1;
 529
 530         /* get direct node */
 531         page = get_node_page(sbi, dn->nid);
 532         if (IS_ERR(page) && PTR_ERR(page) == -ENOENT)
 533                 return 1;
 534         else if (IS_ERR(page))
 535                 return PTR_ERR(page);
 536
 537         /* Make dnode_of_data for parameter */
 538         dn->node_page = page;
 539         dn->ofs_in_node = 0;
 540         truncate_data_blocks(dn);
 541         truncate_node(dn);
 542         return 1;
 543 }
 544
 545 static int truncate_nodes(struct dnode_of_data *dn, unsigned int nofs,
 546                                                 int ofs, int depth)
 547 {
 548         struct f2fs_sb_info *sbi = F2FS_SB(dn->inode->i_sb);
 549         struct dnode_of_data rdn = *dn;
 550         struct page *page;
 551         struct f2fs_node *rn;
 552         nid_t child_nid;
 553         unsigned int child_nofs;
 554         int freed = 0;
 555         int i, ret;
 556
 557         if (dn->nid == 0)
 558                 return NIDS_PER_BLOCK + 1;
 559
 560         trace_f2fs_truncate_nodes_enter(dn->inode, dn->nid, dn->data_blkaddr);
 561
 562         page = get_node_page(sbi, dn->nid);
 563         if (IS_ERR(page)) {
 564                 trace_f2fs_truncate_nodes_exit(dn->inode, PTR_ERR(page));
 565                 return PTR_ERR(page);
 566         }
 567
 568         rn = (struct f2fs_node *)page_address(page);
 569         if (depth < 3) {
 570                 for (i = ofs; i < NIDS_PER_BLOCK; i++, freed++) {
 571                         child_nid = le32_to_cpu(rn->in.nid[i]);
 572                         if (child_nid == 0)
 573                                 continue;
 574                         rdn.nid = child_nid;
 575                         ret = truncate_dnode(&rdn);
 576                         if (ret < 0)
 577                                 goto out_err;
 578                         set_nid(page, i, 0, false);
 579                 }
 580         } else {
 581                 child_nofs = nofs + ofs * (NIDS_PER_BLOCK + 1) + 1;
 582                 for (i = ofs; i < NIDS_PER_BLOCK; i++) {
 583                         child_nid = le32_to_cpu(rn->in.nid[i]);
 584                         if (child_nid == 0) {
 585                                 child_nofs += NIDS_PER_BLOCK + 1;
 586                                 continue;
 587                         }
 588                         rdn.nid = child_nid;
 589                         ret = truncate_nodes(&rdn, child_nofs, 0, depth - 1);
 590                         if (ret == (NIDS_PER_BLOCK + 1)) {
 591                                 set_nid(page, i, 0, false);
 592                                 child_nofs += ret;
 593                         } else if (ret < 0 && ret != -ENOENT) {
 594                                 goto out_err;
 595                         }
 596                 }
 597                 freed = child_nofs;
 598         }
 599
 600         if (!ofs) {
 601                 /* remove current indirect node */
 602                 dn->node_page = page;
 603                 truncate_node(dn);
 604                 freed++;
 605         } else {
 606                 f2fs_put_page(page, 1);
 607         }
 608         trace_f2fs_truncate_nodes_exit(dn->inode, freed);
 609         return freed;
 610
 611 out_err:
 612         f2fs_put_page(page, 1);
 613         trace_f2fs_truncate_nodes_exit(dn->inode, ret);
 614         return ret;
 615 }
 616
 617 static int truncate_partial_nodes(struct dnode_of_data *dn,
 618                         struct f2fs_inode *ri, int *offset, int depth)
 619 {
 620         struct f2fs_sb_info *sbi = F2FS_SB(dn->inode->i_sb);
 621         struct page *pages[2];
 622         nid_t nid[3];
 623         nid_t child_nid;
 624         int err = 0;
 625         int i;
 626         int idx = depth - 2;
 627
 628         nid[0] = le32_to_cpu(ri->i_nid[offset[0] - NODE_DIR1_BLOCK]);
 629         if (!nid[0])
 630                 return 0;
 631
 632         /* get indirect nodes in the path */
 633         for (i = 0; i < depth - 1; i++) {
 634                 /* refernece count'll be increased */
 635                 pages[i] = get_node_page(sbi, nid[i]);
 636                 if (IS_ERR(pages[i])) {
 637                         depth = i + 1;
 638                         err = PTR_ERR(pages[i]);
 639                         goto fail;
 640                 }
 641                 nid[i + 1] = get_nid(pages[i], offset[i + 1], false);
 642         }
 643
 644         /* free direct nodes linked to a partial indirect node */
 645         for (i = offset[depth - 1]; i < NIDS_PER_BLOCK; i++) {
 646                 child_nid = get_nid(pages[idx], i, false);
 647                 if (!child_nid)
 648                         continue;
 649                 dn->nid = child_nid;
 650                 err = truncate_dnode(dn);
 651                 if (err < 0)
 652                         goto fail;
 653                 set_nid(pages[idx], i, 0, false);
 654         }
 655
 656         if (offset[depth - 1] == 0) {
 657                 dn->node_page = pages[idx];
 658                 dn->nid = nid[idx];
 659                 truncate_node(dn);
 660         } else {
 661                 f2fs_put_page(pages[idx], 1);
 662         }
 663         offset[idx]++;
 664         offset[depth - 1] = 0;
 665 fail:
 666         for (i = depth - 3; i >= 0; i--)
 667                 f2fs_put_page(pages[i], 1);
 668
 669         trace_f2fs_truncate_partial_nodes(dn->inode, nid, depth, err);
 670
 671         return err;
 672 }
 673
 674 /*
 675  * All the block addresses of data and nodes should be nullified.
 676  */
 677 int truncate_inode_blocks(struct inode *inode, pgoff_t from)
 678 {
 679         struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
 680         struct address_space *node_mapping = sbi->node_inode->i_mapping;
 681         int err = 0, cont = 1;
 682         int level, offset[4], noffset[4];
 683         unsigned int nofs = 0;
 684         struct f2fs_node *rn;
 685         struct dnode_of_data dn;
 686         struct page *page;
 687
 688         trace_f2fs_truncate_inode_blocks_enter(inode, from);
 689
 690         level = get_node_path(from, offset, noffset);
 691 restart:
 692         page = get_node_page(sbi, inode->i_ino);
 693         if (IS_ERR(page)) {
 694                 trace_f2fs_truncate_inode_blocks_exit(inode, PTR_ERR(page));
 695                 return PTR_ERR(page);
 696         }
 697
 698         set_new_dnode(&dn, inode, page, NULL, 0);
 699         unlock_page(page);
 700
 701         rn = page_address(page);
 702         switch (level) {
 703         case 0:
 704         case 1:
 705                 nofs = noffset[1];
 706                 break;
 707         case 2:
 708                 nofs = noffset[1];
 709                 if (!offset[level - 1])
 710                         goto skip_partial;
 711                 err = truncate_partial_nodes(&dn, &rn->i, offset, level);
 712                 if (err < 0 && err != -ENOENT)
 713                         goto fail;
 714                 nofs += 1 + NIDS_PER_BLOCK;
 715                 break;
 716         case 3:
 717                 nofs = 5 + 2 * NIDS_PER_BLOCK;
 718                 if (!offset[level - 1])
 719                         goto skip_partial;
 720                 err = truncate_partial_nodes(&dn, &rn->i, offset, level);
 721                 if (err < 0 && err != -ENOENT)
 722                         goto fail;
 723                 break;
 724         default:
 725                 BUG();
 726         }
 727
 728 skip_partial:
 729         while (cont) {
 730                 dn.nid = le32_to_cpu(rn->i.i_nid[offset[0] - NODE_DIR1_BLOCK]);
 731                 switch (offset[0]) {
 732                 case NODE_DIR1_BLOCK:
 733                 case NODE_DIR2_BLOCK:
 734                         err = truncate_dnode(&dn);
 735                         break;
 736
 737                 case NODE_IND1_BLOCK:
 738                 case NODE_IND2_BLOCK:
 739                         err = truncate_nodes(&dn, nofs, offset[1], 2);
 740                         break;
 741
 742                 case NODE_DIND_BLOCK:
 743                         err = truncate_nodes(&dn, nofs, offset[1], 3);
 744                         cont = 0;
 745                         break;
 746
 747                 default:
 748                         BUG();
 749                 }
 750                 if (err < 0 && err != -ENOENT)
 751                         goto fail;
 752                 if (offset[1] == 0 &&
 753                                 rn->i.i_nid[offset[0] - NODE_DIR1_BLOCK]) {
 754                         lock_page(page);
 755                         if (page->mapping != node_mapping) {
 756                                 f2fs_put_page(page, 1);
 757                                 goto restart;
 758                         }
 759                         wait_on_page_writeback(page);
 760                         rn->i.i_nid[offset[0] - NODE_DIR1_BLOCK] = 0;
 761                         set_page_dirty(page);
 762                         unlock_page(page);
 763                 }
 764                 offset[1] = 0;
 765                 offset[0]++;
 766                 nofs += err;
 767         }
 768 fail:
 769         f2fs_put_page(page, 0);
 770         trace_f2fs_truncate_inode_blocks_exit(inode, err);
 771         return err > 0 ? 0 : err;
 772 }
 773
 774 /*
 775  * Caller should grab and release a mutex by calling mutex_lock_op() and
 776  * mutex_unlock_op().
 777  */
 778 int remove_inode_page(struct inode *inode)
 779 {
 780         struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
 781         struct page *page;
 782         nid_t ino = inode->i_ino;
 783         struct dnode_of_data dn;
 784
 785         page = get_node_page(sbi, ino);
 786         if (IS_ERR(page))
 787                 return PTR_ERR(page);
 788
 789         if (F2FS_I(inode)->i_xattr_nid) {
 790                 nid_t nid = F2FS_I(inode)->i_xattr_nid;
 791                 struct page *npage = get_node_page(sbi, nid);
 792
 793                 if (IS_ERR(npage))
 794                         return PTR_ERR(npage);
 795
 796                 F2FS_I(inode)->i_xattr_nid = 0;
 797                 set_new_dnode(&dn, inode, page, npage, nid);
 798                 dn.inode_page_locked = 1;
 799                 truncate_node(&dn);
 800         }
 801
 802         /* 0 is possible, after f2fs_new_inode() is failed */
 803         BUG_ON(inode->i_blocks != 0 && inode->i_blocks != 1);
 804         set_new_dnode(&dn, inode, page, page, ino);
 805         truncate_node(&dn);
 806         return 0;
 807 }
 808
 809 struct page *new_inode_page(struct inode *inode, const struct qstr *name)
 810 {
 811         struct dnode_of_data dn;
 812
 813         /* allocate inode page for new inode */
 814         set_new_dnode(&dn, inode, NULL, NULL, inode->i_ino);
 815
 816         /* caller should f2fs_put_page(page, 1); */
 817         return new_node_page(&dn, 0, NULL);
 818 }
 819
 820 struct page *new_node_page(struct dnode_of_data *dn,
 821                                 unsigned int ofs, struct page *ipage)
 822 {
 823         struct f2fs_sb_info *sbi = F2FS_SB(dn->inode->i_sb);
 824         struct address_space *mapping = sbi->node_inode->i_mapping;
 825         struct node_info old_ni, new_ni;
 826         struct page *page;
 827         int err;
 828
 829         if (is_inode_flag_set(F2FS_I(dn->inode), FI_NO_ALLOC))
 830                 return ERR_PTR(-EPERM);
 831
 832         page = grab_cache_page(mapping, dn->nid);
 833         if (!page)
 834                 return ERR_PTR(-ENOMEM);
 835
 836         get_node_info(sbi, dn->nid, &old_ni);
 837
 838         SetPageUptodate(page);
 839         fill_node_footer(page, dn->nid, dn->inode->i_ino, ofs, true);
 840
 841         /* Reinitialize old_ni with new node page */
 842         BUG_ON(old_ni.blk_addr != NULL_ADDR);
 843         new_ni = old_ni;
 844         new_ni.ino = dn->inode->i_ino;
 845
 846         if (!inc_valid_node_count(sbi, dn->inode, 1)) {
 847                 err = -ENOSPC;
 848                 goto fail;
 849         }
 850         set_node_addr(sbi, &new_ni, NEW_ADDR);
 851         set_cold_node(dn->inode, page);
 852
 853         dn->node_page = page;
 854         if (ipage)
 855                 update_inode(dn->inode, ipage);
 856         else
 857                 sync_inode_page(dn);
 858         set_page_dirty(page);
 859         if (ofs == 0)
 860                 inc_valid_inode_count(sbi);
 861
 862         return page;
 863
 864 fail:
 865         clear_node_page_dirty(page);
 866         f2fs_put_page(page, 1);
 867         return ERR_PTR(err);
 868 }
 869
 870 /*
 871  * Caller should do after getting the following values.
 872  * 0: f2fs_put_page(page, 0)
 873  * LOCKED_PAGE: f2fs_put_page(page, 1)
 874  * error: nothing
 875  */
 876 static int read_node_page(struct page *page, int type)
 877 {
 878         struct f2fs_sb_info *sbi = F2FS_SB(page->mapping->host->i_sb);
 879         struct node_info ni;
 880
 881         get_node_info(sbi, page->index, &ni);
 882
 883         if (ni.blk_addr == NULL_ADDR) {
 884                 f2fs_put_page(page, 1);
 885                 return -ENOENT;
 886         }
 887
 888         if (PageUptodate(page))
 889                 return LOCKED_PAGE;
 890
 891         return f2fs_readpage(sbi, page, ni.blk_addr, type);
 892 }
 893
 894 /*
 895  * Readahead a node page
 896  */
 897 void ra_node_page(struct f2fs_sb_info *sbi, nid_t nid)
 898 {
 899         struct address_space *mapping = sbi->node_inode->i_mapping;
 900         struct page *apage;
 901         int err;
 902
 903         apage = find_get_page(mapping, nid);
 904         if (apage && PageUptodate(apage)) {
 905                 f2fs_put_page(apage, 0);
 906                 return;
 907         }
 908         f2fs_put_page(apage, 0);
 909
 910         apage = grab_cache_page(mapping, nid);
 911         if (!apage)
 912                 return;
 913
 914         err = read_node_page(apage, READA);
 915         if (err == 0)
 916                 f2fs_put_page(apage, 0);
 917         else if (err == LOCKED_PAGE)
 918                 f2fs_put_page(apage, 1);
 919         return;
 920 }
 921
 922 struct page *get_node_page(struct f2fs_sb_info *sbi, pgoff_t nid)
 923 {
 924         struct address_space *mapping = sbi->node_inode->i_mapping;
 925         struct page *page;
 926         int err;
 927 repeat:
 928         page = grab_cache_page(mapping, nid);
 929         if (!page)
 930                 return ERR_PTR(-ENOMEM);
 931
 932         err = read_node_page(page, READ_SYNC);
 933         if (err < 0)
 934                 return ERR_PTR(err);
 935         else if (err == LOCKED_PAGE)
 936                 goto got_it;
 937
 938         lock_page(page);
 939         if (!PageUptodate(page)) {
 940                 f2fs_put_page(page, 1);
 941                 return ERR_PTR(-EIO);
 942         }
 943         if (page->mapping != mapping) {
 944                 f2fs_put_page(page, 1);
 945                 goto repeat;
 946         }
 947 got_it:
 948         BUG_ON(nid != nid_of_node(page));
 949         mark_page_accessed(page);
 950         return page;
 951 }
 952
 953 /*
 954  * Return a locked page for the desired node page.
 955  * And, readahead MAX_RA_NODE number of node pages.
 956  */
 957 struct page *get_node_page_ra(struct page *parent, int start)
 958 {
 959         struct f2fs_sb_info *sbi = F2FS_SB(parent->mapping->host->i_sb);
 960         struct address_space *mapping = sbi->node_inode->i_mapping;
 961         struct blk_plug plug;
 962         struct page *page;
 963         int err, i, end;
 964         nid_t nid;
 965
 966         /* First, try getting the desired direct node. */
 967         nid = get_nid(parent, start, false);
 968         if (!nid)
 969                 return ERR_PTR(-ENOENT);
 970 repeat:
 971         page = grab_cache_page(mapping, nid);
 972         if (!page)
 973                 return ERR_PTR(-ENOMEM);
 974
 975         err = read_node_page(page, READ_SYNC);
 976         if (err < 0)
 977                 return ERR_PTR(err);
 978         else if (err == LOCKED_PAGE)
 979                 goto page_hit;
 980
 981         blk_start_plug(&plug);
 982
 983         /* Then, try readahead for siblings of the desired node */
 984         end = start + MAX_RA_NODE;
 985         end = min(end, NIDS_PER_BLOCK);
 986         for (i = start + 1; i < end; i++) {
 987                 nid = get_nid(parent, i, false);
 988                 if (!nid)
 989                         continue;
 990                 ra_node_page(sbi, nid);
 991         }
 992
 993         blk_finish_plug(&plug);
 994
 995         lock_page(page);
 996         if (page->mapping != mapping) {
 997                 f2fs_put_page(page, 1);
 998                 goto repeat;
 999         }
1000 page_hit:
1001         if (!PageUptodate(page)) {
1002                 f2fs_put_page(page, 1);
1003                 return ERR_PTR(-EIO);
1004         }
1005         mark_page_accessed(page);
1006         return page;
1007 }
1008
1009 void sync_inode_page(struct dnode_of_data *dn)
1010 {
1011         if (IS_INODE(dn->node_page) || dn->inode_page == dn->node_page) {
1012                 update_inode(dn->inode, dn->node_page);
1013         } else if (dn->inode_page) {
1014                 if (!dn->inode_page_locked)
1015                         lock_page(dn->inode_page);
1016                 update_inode(dn->inode, dn->inode_page);
1017                 if (!dn->inode_page_locked)
1018                         unlock_page(dn->inode_page);
1019         } else {
1020                 update_inode_page(dn->inode);
1021         }
1022 }
1023
1024 int sync_node_pages(struct f2fs_sb_info *sbi, nid_t ino,
1025                                         struct writeback_control *wbc)
1026 {
1027         struct address_space *mapping = sbi->node_inode->i_mapping;
1028         pgoff_t index, end;
1029         struct pagevec pvec;
1030         int step = ino ? 2 : 0;
1031         int nwritten = 0, wrote = 0;
1032
1033         pagevec_init(&pvec, 0);
1034
1035 next_step:
1036         index = 0;
1037         end = LONG_MAX;
1038
1039         while (index <= end) {
1040                 int i, nr_pages;
1041                 nr_pages = pagevec_lookup_tag(&pvec, mapping, &index,
1042                                 PAGECACHE_TAG_DIRTY,
1043                                 min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1);
1044                 if (nr_pages == 0)
1045                         break;
1046
1047                 for (i = 0; i < nr_pages; i++) {
1048                         struct page *page = pvec.pages[i];
1049
1050                         /*
1051                          * flushing sequence with step:
1052                          * 0. indirect nodes
1053                          * 1. dentry dnodes
1054                          * 2. file dnodes
1055                          */
1056                         if (step == 0 && IS_DNODE(page))
1057                                 continue;
1058                         if (step == 1 && (!IS_DNODE(page) ||
1059                                                 is_cold_node(page)))
1060                                 continue;
1061                         if (step == 2 && (!IS_DNODE(page) ||
1062                                                 !is_cold_node(page)))
1063                                 continue;
1064
1065                         /*
1066                          * If an fsync mode,
1067                          * we should not skip writing node pages.
1068                          */
1069                         if (ino && ino_of_node(page) == ino)
1070                                 lock_page(page);
1071                         else if (!trylock_page(page))
1072                                 continue;
1073
1074                         if (unlikely(page->mapping != mapping)) {
1075 continue_unlock:
1076                                 unlock_page(page);
1077                                 continue;
1078                         }
1079                         if (ino && ino_of_node(page) != ino)
1080                                 goto continue_unlock;
1081
1082                         if (!PageDirty(page)) {
1083                                 /* someone wrote it for us */
1084                                 goto continue_unlock;
1085                         }
1086
1087                         if (!clear_page_dirty_for_io(page))
1088                                 goto continue_unlock;
1089
1090                         /* called by fsync() */
1091                         if (ino && IS_DNODE(page)) {
1092                                 int mark = !is_checkpointed_node(sbi, ino);
1093                                 set_fsync_mark(page, 1);
1094                                 if (IS_INODE(page))
1095                                         set_dentry_mark(page, mark);
1096                                 nwritten++;
1097                         } else {
1098                                 set_fsync_mark(page, 0);
1099                                 set_dentry_mark(page, 0);
1100                         }
1101                         mapping->a_ops->writepage(page, wbc);
1102                         wrote++;
1103
1104                         if (--wbc->nr_to_write == 0)
1105                                 break;
1106                 }
1107                 pagevec_release(&pvec);
1108                 cond_resched();
1109
1110                 if (wbc->nr_to_write == 0) {
1111                         step = 2;
1112                         break;
1113                 }
1114         }
1115
1116         if (step < 2) {
1117                 step++;
1118                 goto next_step;
1119         }
1120
1121         if (wrote)
1122                 f2fs_submit_bio(sbi, NODE, wbc->sync_mode == WB_SYNC_ALL);
1123
1124         return nwritten;
1125 }
1126
1127 static int f2fs_write_node_page(struct page *page,
1128                                 struct writeback_control *wbc)
1129 {
1130         struct f2fs_sb_info *sbi = F2FS_SB(page->mapping->host->i_sb);
1131         nid_t nid;
1132         block_t new_addr;
1133         struct node_info ni;
1134
1135         wait_on_page_writeback(page);
1136
1137         /* get old block addr of this node page */
1138         nid = nid_of_node(page);
1139         BUG_ON(page->index != nid);
1140
1141         get_node_info(sbi, nid, &ni);
1142
1143         /* This page is already truncated */
1144         if (ni.blk_addr == NULL_ADDR) {
1145                 dec_page_count(sbi, F2FS_DIRTY_NODES);
1146                 unlock_page(page);
1147                 return 0;
1148         }
1149
1150         if (wbc->for_reclaim) {
1151                 dec_page_count(sbi, F2FS_DIRTY_NODES);
1152                 wbc->pages_skipped++;
1153                 set_page_dirty(page);
1154                 return AOP_WRITEPAGE_ACTIVATE;
1155         }
1156
1157         mutex_lock(&sbi->node_write);
1158         set_page_writeback(page);
1159         write_node_page(sbi, page, nid, ni.blk_addr, &new_addr);
1160         set_node_addr(sbi, &ni, new_addr);
1161         dec_page_count(sbi, F2FS_DIRTY_NODES);
1162         mutex_unlock(&sbi->node_write);
1163         unlock_page(page);
1164         return 0;
1165 }
1166
1167 /*
1168  * It is very important to gather dirty pages and write at once, so that we can
1169  * submit a big bio without interfering other data writes.
1170  * Be default, 512 pages (2MB), a segment size, is quite reasonable.
1171  */
1172 #define COLLECT_DIRTY_NODES     512
1173 static int f2fs_write_node_pages(struct address_space *mapping,
1174                             struct writeback_control *wbc)
1175 {
1176         struct f2fs_sb_info *sbi = F2FS_SB(mapping->host->i_sb);
1177         long nr_to_write = wbc->nr_to_write;
1178
1179         /* First check balancing cached NAT entries */
1180         if (try_to_free_nats(sbi, NAT_ENTRY_PER_BLOCK)) {
1181                 f2fs_sync_fs(sbi->sb, true);
1182                 return 0;
1183         }
1184
1185         /* collect a number of dirty node pages and write together */
1186         if (get_pages(sbi, F2FS_DIRTY_NODES) < COLLECT_DIRTY_NODES)
1187                 return 0;
1188
1189         /* if mounting is failed, skip writing node pages */
1190         wbc->nr_to_write = max_hw_blocks(sbi);
1191         sync_node_pages(sbi, 0, wbc);
1192         wbc->nr_to_write = nr_to_write - (max_hw_blocks(sbi) - wbc->nr_to_write);
1193         return 0;
1194 }
1195
1196 static int f2fs_set_node_page_dirty(struct page *page)
1197 {
1198         struct address_space *mapping = page->mapping;
1199         struct f2fs_sb_info *sbi = F2FS_SB(mapping->host->i_sb);
1200
1201         SetPageUptodate(page);
1202         if (!PageDirty(page)) {
1203                 __set_page_dirty_nobuffers(page);
1204                 inc_page_count(sbi, F2FS_DIRTY_NODES);
1205                 SetPagePrivate(page);
1206                 return 1;
1207         }
1208         return 0;
1209 }
1210
1211 static void f2fs_invalidate_node_page(struct page *page, unsigned int offset,
1212                                       unsigned int length)
1213 {
1214         struct inode *inode = page->mapping->host;
1215         struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
1216         if (PageDirty(page))
1217                 dec_page_count(sbi, F2FS_DIRTY_NODES);
1218         ClearPagePrivate(page);
1219 }
1220
1221 static int f2fs_release_node_page(struct page *page, gfp_t wait)
1222 {
1223         ClearPagePrivate(page);
1224         return 1;
1225 }
1226
1227 /*
1228  * Structure of the f2fs node operations
1229  */
1230 const struct address_space_operations f2fs_node_aops = {
1231         .writepage      = f2fs_write_node_page,
1232         .writepages     = f2fs_write_node_pages,
1233         .set_page_dirty = f2fs_set_node_page_dirty,
1234         .invalidatepage = f2fs_invalidate_node_page,
1235         .releasepage    = f2fs_release_node_page,
1236 };
1237
1238 static struct free_nid *__lookup_free_nid_list(nid_t n, struct list_head *head)
1239 {
1240         struct list_head *this;
1241         struct free_nid *i;
1242         list_for_each(this, head) {
1243                 i = list_entry(this, struct free_nid, list);
1244                 if (i->nid == n)
1245                         return i;
1246         }
1247         return NULL;
1248 }
1249
1250 static void __del_from_free_nid_list(struct free_nid *i)
1251 {
1252         list_del(&i->list);
1253         kmem_cache_free(free_nid_slab, i);
1254 }
1255
1256 static int add_free_nid(struct f2fs_nm_info *nm_i, nid_t nid, bool build)
1257 {
1258         struct free_nid *i;
1259         struct nat_entry *ne;
1260         bool allocated = false;
1261
1262         if (nm_i->fcnt > 2 * MAX_FREE_NIDS)
1263                 return -1;
1264
1265         /* 0 nid should not be used */
1266         if (nid == 0)
1267                 return 0;
1268
1269         if (!build)
1270                 goto retry;
1271
1272         /* do not add allocated nids */
1273         read_lock(&nm_i->nat_tree_lock);
1274         ne = __lookup_nat_cache(nm_i, nid);
1275         if (ne && nat_get_blkaddr(ne) != NULL_ADDR)
1276                 allocated = true;
1277         read_unlock(&nm_i->nat_tree_lock);
1278         if (allocated)
1279                 return 0;
1280 retry:
1281         i = kmem_cache_alloc(free_nid_slab, GFP_NOFS);
1282         if (!i) {
1283                 cond_resched();
1284                 goto retry;
1285         }
1286         i->nid = nid;
1287         i->state = NID_NEW;
1288
1289         spin_lock(&nm_i->free_nid_list_lock);
1290         if (__lookup_free_nid_list(nid, &nm_i->free_nid_list)) {
1291                 spin_unlock(&nm_i->free_nid_list_lock);
1292                 kmem_cache_free(free_nid_slab, i);
1293                 return 0;
1294         }
1295         list_add_tail(&i->list, &nm_i->free_nid_list);
1296         nm_i->fcnt++;
1297         spin_unlock(&nm_i->free_nid_list_lock);
1298         return 1;
1299 }
1300
1301 static void remove_free_nid(struct f2fs_nm_info *nm_i, nid_t nid)
1302 {
1303         struct free_nid *i;
1304         spin_lock(&nm_i->free_nid_list_lock);
1305         i = __lookup_free_nid_list(nid, &nm_i->free_nid_list);
1306         if (i && i->state == NID_NEW) {
1307                 __del_from_free_nid_list(i);
1308                 nm_i->fcnt--;
1309         }
1310         spin_unlock(&nm_i->free_nid_list_lock);
1311 }
1312
1313 static void scan_nat_page(struct f2fs_nm_info *nm_i,
1314                         struct page *nat_page, nid_t start_nid)
1315 {
1316         struct f2fs_nat_block *nat_blk = page_address(nat_page);
1317         block_t blk_addr;
1318         int i;
1319
1320         i = start_nid % NAT_ENTRY_PER_BLOCK;
1321
1322         for (; i < NAT_ENTRY_PER_BLOCK; i++, start_nid++) {
1323
1324                 if (start_nid >= nm_i->max_nid)
1325                         break;
1326
1327                 blk_addr = le32_to_cpu(nat_blk->entries[i].block_addr);
1328                 BUG_ON(blk_addr == NEW_ADDR);
1329                 if (blk_addr == NULL_ADDR) {
1330                         if (add_free_nid(nm_i, start_nid, true) < 0)
1331                                 break;
1332                 }
1333         }
1334 }
1335
1336 static void build_free_nids(struct f2fs_sb_info *sbi)
1337 {
1338         struct f2fs_nm_info *nm_i = NM_I(sbi);
1339         struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_HOT_DATA);
1340         struct f2fs_summary_block *sum = curseg->sum_blk;
1341         int i = 0;
1342         nid_t nid = nm_i->next_scan_nid;
1343
1344         /* Enough entries */
1345         if (nm_i->fcnt > NAT_ENTRY_PER_BLOCK)
1346                 return;
1347
1348         /* readahead nat pages to be scanned */
1349         ra_nat_pages(sbi, nid);
1350
1351         while (1) {
1352                 struct page *page = get_current_nat_page(sbi, nid);
1353
1354                 scan_nat_page(nm_i, page, nid);
1355                 f2fs_put_page(page, 1);
1356
1357                 nid += (NAT_ENTRY_PER_BLOCK - (nid % NAT_ENTRY_PER_BLOCK));
1358                 if (nid >= nm_i->max_nid)
1359                         nid = 0;
1360
1361                 if (i++ == FREE_NID_PAGES)
1362                         break;
1363         }
1364
1365         /* go to the next free nat pages to find free nids abundantly */
1366         nm_i->next_scan_nid = nid;
1367
1368         /* find free nids from current sum_pages */
1369         mutex_lock(&curseg->curseg_mutex);
1370         for (i = 0; i < nats_in_cursum(sum); i++) {
1371                 block_t addr = le32_to_cpu(nat_in_journal(sum, i).block_addr);
1372                 nid = le32_to_cpu(nid_in_journal(sum, i));
1373                 if (addr == NULL_ADDR)
1374                         add_free_nid(nm_i, nid, true);
1375                 else
1376                         remove_free_nid(nm_i, nid);
1377         }
1378         mutex_unlock(&curseg->curseg_mutex);
1379 }
1380
1381 /*
1382  * If this function returns success, caller can obtain a new nid
1383  * from second parameter of this function.
1384  * The returned nid could be used ino as well as nid when inode is created.
1385  */
1386 bool alloc_nid(struct f2fs_sb_info *sbi, nid_t *nid)
1387 {
1388         struct f2fs_nm_info *nm_i = NM_I(sbi);
1389         struct free_nid *i = NULL;
1390         struct list_head *this;
1391 retry:
1392         if (sbi->total_valid_node_count + 1 >= nm_i->max_nid)
1393                 return false;
1394
1395         spin_lock(&nm_i->free_nid_list_lock);
1396
1397         /* We should not use stale free nids created by build_free_nids */
1398         if (nm_i->fcnt && !sbi->on_build_free_nids) {
1399                 BUG_ON(list_empty(&nm_i->free_nid_list));
1400                 list_for_each(this, &nm_i->free_nid_list) {
1401                         i = list_entry(this, struct free_nid, list);
1402                         if (i->state == NID_NEW)
1403                                 break;
1404                 }
1405
1406                 BUG_ON(i->state != NID_NEW);
1407                 *nid = i->nid;
1408                 i->state = NID_ALLOC;
1409                 nm_i->fcnt--;
1410                 spin_unlock(&nm_i->free_nid_list_lock);
1411                 return true;
1412         }
1413         spin_unlock(&nm_i->free_nid_list_lock);
1414
1415         /* Let's scan nat pages and its caches to get free nids */
1416         mutex_lock(&nm_i->build_lock);
1417         sbi->on_build_free_nids = 1;
1418         build_free_nids(sbi);
1419         sbi->on_build_free_nids = 0;
1420         mutex_unlock(&nm_i->build_lock);
1421         goto retry;
1422 }
1423
1424 /*
1425  * alloc_nid() should be called prior to this function.
1426  */
1427 void alloc_nid_done(struct f2fs_sb_info *sbi, nid_t nid)
1428 {
1429         struct f2fs_nm_info *nm_i = NM_I(sbi);
1430         struct free_nid *i;
1431
1432         spin_lock(&nm_i->free_nid_list_lock);
1433         i = __lookup_free_nid_list(nid, &nm_i->free_nid_list);
1434         BUG_ON(!i || i->state != NID_ALLOC);
1435         __del_from_free_nid_list(i);
1436         spin_unlock(&nm_i->free_nid_list_lock);
1437 }
1438
1439 /*
1440  * alloc_nid() should be called prior to this function.
1441  */
1442 void alloc_nid_failed(struct f2fs_sb_info *sbi, nid_t nid)
1443 {
1444         struct f2fs_nm_info *nm_i = NM_I(sbi);
1445         struct free_nid *i;
1446
1447         spin_lock(&nm_i->free_nid_list_lock);
1448         i = __lookup_free_nid_list(nid, &nm_i->free_nid_list);
1449         BUG_ON(!i || i->state != NID_ALLOC);
1450         if (nm_i->fcnt > 2 * MAX_FREE_NIDS) {
1451                 __del_from_free_nid_list(i);
1452         } else {
1453                 i->state = NID_NEW;
1454                 nm_i->fcnt++;
1455         }
1456         spin_unlock(&nm_i->free_nid_list_lock);
1457 }
1458
1459 void recover_node_page(struct f2fs_sb_info *sbi, struct page *page,
1460                 struct f2fs_summary *sum, struct node_info *ni,
1461                 block_t new_blkaddr)
1462 {
1463         rewrite_node_page(sbi, page, sum, ni->blk_addr, new_blkaddr);
1464         set_node_addr(sbi, ni, new_blkaddr);
1465         clear_node_page_dirty(page);
1466 }
1467
1468 int recover_inode_page(struct f2fs_sb_info *sbi, struct page *page)
1469 {
1470         struct address_space *mapping = sbi->node_inode->i_mapping;
1471         struct f2fs_node *src, *dst;
1472         nid_t ino = ino_of_node(page);
1473         struct node_info old_ni, new_ni;
1474         struct page *ipage;
1475
1476         ipage = grab_cache_page(mapping, ino);
1477         if (!ipage)
1478                 return -ENOMEM;
1479
1480         /* Should not use this inode  from free nid list */
1481         remove_free_nid(NM_I(sbi), ino);
1482
1483         get_node_info(sbi, ino, &old_ni);
1484         SetPageUptodate(ipage);
1485         fill_node_footer(ipage, ino, ino, 0, true);
1486
1487         src = (struct f2fs_node *)page_address(page);
1488         dst = (struct f2fs_node *)page_address(ipage);
1489
1490         memcpy(dst, src, (unsigned long)&src->i.i_ext - (unsigned long)&src->i);
1491         dst->i.i_size = 0;
1492         dst->i.i_blocks = cpu_to_le64(1);
1493         dst->i.i_links = cpu_to_le32(1);
1494         dst->i.i_xattr_nid = 0;
1495
1496         new_ni = old_ni;
1497         new_ni.ino = ino;
1498
1499         if (!inc_valid_node_count(sbi, NULL, 1))
1500                 WARN_ON(1);
1501         set_node_addr(sbi, &new_ni, NEW_ADDR);
1502         inc_valid_inode_count(sbi);
1503         f2fs_put_page(ipage, 1);
1504         return 0;
1505 }
1506
1507 int restore_node_summary(struct f2fs_sb_info *sbi,
1508                         unsigned int segno, struct f2fs_summary_block *sum)
1509 {
1510         struct f2fs_node *rn;
1511         struct f2fs_summary *sum_entry;
1512         struct page *page;
1513         block_t addr;
1514         int i, last_offset;
1515
1516         /* alloc temporal page for read node */
1517         page = alloc_page(GFP_NOFS | __GFP_ZERO);
1518         if (IS_ERR(page))
1519                 return PTR_ERR(page);
1520         lock_page(page);
1521
1522         /* scan the node segment */
1523         last_offset = sbi->blocks_per_seg;
1524         addr = START_BLOCK(sbi, segno);
1525         sum_entry = &sum->entries[0];
1526
1527         for (i = 0; i < last_offset; i++, sum_entry++) {
1528                 /*
1529                  * In order to read next node page,
1530                  * we must clear PageUptodate flag.
1531                  */
1532                 ClearPageUptodate(page);
1533
1534                 if (f2fs_readpage(sbi, page, addr, READ_SYNC))
1535                         goto out;
1536
1537                 lock_page(page);
1538                 rn = (struct f2fs_node *)page_address(page);
1539                 sum_entry->nid = rn->footer.nid;
1540                 sum_entry->version = 0;
1541                 sum_entry->ofs_in_node = 0;
1542                 addr++;
1543         }
1544         unlock_page(page);
1545 out:
1546         __free_pages(page, 0);
1547         return 0;
1548 }
1549
1550 static bool flush_nats_in_journal(struct f2fs_sb_info *sbi)
1551 {
1552         struct f2fs_nm_info *nm_i = NM_I(sbi);
1553         struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_HOT_DATA);
1554         struct f2fs_summary_block *sum = curseg->sum_blk;
1555         int i;
1556
1557         mutex_lock(&curseg->curseg_mutex);
1558
1559         if (nats_in_cursum(sum) < NAT_JOURNAL_ENTRIES) {
1560                 mutex_unlock(&curseg->curseg_mutex);
1561                 return false;
1562         }
1563
1564         for (i = 0; i < nats_in_cursum(sum); i++) {
1565                 struct nat_entry *ne;
1566                 struct f2fs_nat_entry raw_ne;
1567                 nid_t nid = le32_to_cpu(nid_in_journal(sum, i));
1568
1569                 raw_ne = nat_in_journal(sum, i);
1570 retry:
1571                 write_lock(&nm_i->nat_tree_lock);
1572                 ne = __lookup_nat_cache(nm_i, nid);
1573                 if (ne) {
1574                         __set_nat_cache_dirty(nm_i, ne);
1575                         write_unlock(&nm_i->nat_tree_lock);
1576                         continue;
1577                 }
1578                 ne = grab_nat_entry(nm_i, nid);
1579                 if (!ne) {
1580                         write_unlock(&nm_i->nat_tree_lock);
1581                         goto retry;
1582                 }
1583                 nat_set_blkaddr(ne, le32_to_cpu(raw_ne.block_addr));
1584                 nat_set_ino(ne, le32_to_cpu(raw_ne.ino));
1585                 nat_set_version(ne, raw_ne.version);
1586                 __set_nat_cache_dirty(nm_i, ne);
1587                 write_unlock(&nm_i->nat_tree_lock);
1588         }
1589         update_nats_in_cursum(sum, -i);
1590         mutex_unlock(&curseg->curseg_mutex);
1591         return true;
1592 }
1593
1594 /*
1595  * This function is called during the checkpointing process.
1596  */
1597 void flush_nat_entries(struct f2fs_sb_info *sbi)
1598 {
1599         struct f2fs_nm_info *nm_i = NM_I(sbi);
1600         struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_HOT_DATA);
1601         struct f2fs_summary_block *sum = curseg->sum_blk;
1602         struct list_head *cur, *n;
1603         struct page *page = NULL;
1604         struct f2fs_nat_block *nat_blk = NULL;
1605         nid_t start_nid = 0, end_nid = 0;
1606         bool flushed;
1607
1608         flushed = flush_nats_in_journal(sbi);
1609
1610         if (!flushed)
1611                 mutex_lock(&curseg->curseg_mutex);
1612
1613         /* 1) flush dirty nat caches */
1614         list_for_each_safe(cur, n, &nm_i->dirty_nat_entries) {
1615                 struct nat_entry *ne;
1616                 nid_t nid;
1617                 struct f2fs_nat_entry raw_ne;
1618                 int offset = -1;
1619                 block_t new_blkaddr;
1620
1621                 ne = list_entry(cur, struct nat_entry, list);
1622                 nid = nat_get_nid(ne);
1623
1624                 if (nat_get_blkaddr(ne) == NEW_ADDR)
1625                         continue;
1626                 if (flushed)
1627                         goto to_nat_page;
1628
1629                 /* if there is room for nat enries in curseg->sumpage */
1630                 offset = lookup_journal_in_cursum(sum, NAT_JOURNAL, nid, 1);
1631                 if (offset >= 0) {
1632                         raw_ne = nat_in_journal(sum, offset);
1633                         goto flush_now;
1634                 }
1635 to_nat_page:
1636                 if (!page || (start_nid > nid || nid > end_nid)) {
1637                         if (page) {
1638                                 f2fs_put_page(page, 1);
1639                                 page = NULL;
1640                         }
1641                         start_nid = START_NID(nid);
1642                         end_nid = start_nid + NAT_ENTRY_PER_BLOCK - 1;
1643
1644                         /*
1645                          * get nat block with dirty flag, increased reference
1646                          * count, mapped and lock
1647                          */
1648                         page = get_next_nat_page(sbi, start_nid);
1649                         nat_blk = page_address(page);
1650                 }
1651
1652                 BUG_ON(!nat_blk);
1653                 raw_ne = nat_blk->entries[nid - start_nid];
1654 flush_now:
1655                 new_blkaddr = nat_get_blkaddr(ne);
1656
1657                 raw_ne.ino = cpu_to_le32(nat_get_ino(ne));
1658                 raw_ne.block_addr = cpu_to_le32(new_blkaddr);
1659                 raw_ne.version = nat_get_version(ne);
1660
1661                 if (offset < 0) {
1662                         nat_blk->entries[nid - start_nid] = raw_ne;
1663                 } else {
1664                         nat_in_journal(sum, offset) = raw_ne;
1665                         nid_in_journal(sum, offset) = cpu_to_le32(nid);
1666                 }
1667
1668                 if (nat_get_blkaddr(ne) == NULL_ADDR &&
1669                                 add_free_nid(NM_I(sbi), nid, false) <= 0) {
1670                         write_lock(&nm_i->nat_tree_lock);
1671                         __del_from_nat_cache(nm_i, ne);
1672                         write_unlock(&nm_i->nat_tree_lock);
1673                 } else {
1674                         write_lock(&nm_i->nat_tree_lock);
1675                         __clear_nat_cache_dirty(nm_i, ne);
1676                         ne->checkpointed = true;
1677                         write_unlock(&nm_i->nat_tree_lock);
1678                 }
1679         }
1680         if (!flushed)
1681                 mutex_unlock(&curseg->curseg_mutex);
1682         f2fs_put_page(page, 1);
1683
1684         /* 2) shrink nat caches if necessary */
1685         try_to_free_nats(sbi, nm_i->nat_cnt - NM_WOUT_THRESHOLD);
1686 }
1687
1688 static int init_node_manager(struct f2fs_sb_info *sbi)
1689 {
1690         struct f2fs_super_block *sb_raw = F2FS_RAW_SUPER(sbi);
1691         struct f2fs_nm_info *nm_i = NM_I(sbi);
1692         unsigned char *version_bitmap;
1693         unsigned int nat_segs, nat_blocks;
1694
1695         nm_i->nat_blkaddr = le32_to_cpu(sb_raw->nat_blkaddr);
1696
1697         /* segment_count_nat includes pair segment so divide to 2. */
1698         nat_segs = le32_to_cpu(sb_raw->segment_count_nat) >> 1;
1699         nat_blocks = nat_segs << le32_to_cpu(sb_raw->log_blocks_per_seg);
1700         nm_i->max_nid = NAT_ENTRY_PER_BLOCK * nat_blocks;
1701         nm_i->fcnt = 0;
1702         nm_i->nat_cnt = 0;
1703
1704         INIT_LIST_HEAD(&nm_i->free_nid_list);
1705         INIT_RADIX_TREE(&nm_i->nat_root, GFP_ATOMIC);
1706         INIT_LIST_HEAD(&nm_i->nat_entries);
1707         INIT_LIST_HEAD(&nm_i->dirty_nat_entries);
1708
1709         mutex_init(&nm_i->build_lock);
1710         spin_lock_init(&nm_i->free_nid_list_lock);
1711         rwlock_init(&nm_i->nat_tree_lock);
1712
1713         nm_i->next_scan_nid = le32_to_cpu(sbi->ckpt->next_free_nid);
1714         nm_i->bitmap_size = __bitmap_size(sbi, NAT_BITMAP);
1715         version_bitmap = __bitmap_ptr(sbi, NAT_BITMAP);
1716         if (!version_bitmap)
1717                 return -EFAULT;
1718
1719         nm_i->nat_bitmap = kmemdup(version_bitmap, nm_i->bitmap_size,
1720                                         GFP_KERNEL);
1721         if (!nm_i->nat_bitmap)
1722                 return -ENOMEM;
1723         return 0;
1724 }
1725
1726 int build_node_manager(struct f2fs_sb_info *sbi)
1727 {
1728         int err;
1729
1730         sbi->nm_info = kzalloc(sizeof(struct f2fs_nm_info), GFP_KERNEL);
1731         if (!sbi->nm_info)
1732                 return -ENOMEM;
1733
1734         err = init_node_manager(sbi);
1735         if (err)
1736                 return err;
1737
1738         build_free_nids(sbi);
1739         return 0;
1740 }
1741
1742 void destroy_node_manager(struct f2fs_sb_info *sbi)
1743 {
1744         struct f2fs_nm_info *nm_i = NM_I(sbi);
1745         struct free_nid *i, *next_i;
1746         struct nat_entry *natvec[NATVEC_SIZE];
1747         nid_t nid = 0;
1748         unsigned int found;
1749
1750         if (!nm_i)
1751                 return;
1752
1753         /* destroy free nid list */
1754         spin_lock(&nm_i->free_nid_list_lock);
1755         list_for_each_entry_safe(i, next_i, &nm_i->free_nid_list, list) {
1756                 BUG_ON(i->state == NID_ALLOC);
1757                 __del_from_free_nid_list(i);
1758                 nm_i->fcnt--;
1759         }
1760         BUG_ON(nm_i->fcnt);
1761         spin_unlock(&nm_i->free_nid_list_lock);
1762
1763         /* destroy nat cache */
1764         write_lock(&nm_i->nat_tree_lock);
1765         while ((found = __gang_lookup_nat_cache(nm_i,
1766                                         nid, NATVEC_SIZE, natvec))) {
1767                 unsigned idx;
1768                 for (idx = 0; idx < found; idx++) {
1769                         struct nat_entry *e = natvec[idx];
1770                         nid = nat_get_nid(e) + 1;
1771                         __del_from_nat_cache(nm_i, e);
1772                 }
1773         }
1774         BUG_ON(nm_i->nat_cnt);
1775         write_unlock(&nm_i->nat_tree_lock);
1776
1777         kfree(nm_i->nat_bitmap);
1778         sbi->nm_info = NULL;
1779         kfree(nm_i);
1780 }
1781
1782 int __init create_node_manager_caches(void)
1783 {
1784         nat_entry_slab = f2fs_kmem_cache_create("nat_entry",
1785                         sizeof(struct nat_entry), NULL);
1786         if (!nat_entry_slab)
1787                 return -ENOMEM;
1788
1789         free_nid_slab = f2fs_kmem_cache_create("free_nid",
1790                         sizeof(struct free_nid), NULL);
1791         if (!free_nid_slab) {
1792                 kmem_cache_destroy(nat_entry_slab);
1793                 return -ENOMEM;
1794         }
1795         return 0;
1796 }
1797
1798 void destroy_node_manager_caches(void)
1799 {
1800         kmem_cache_destroy(free_nid_slab);
1801         kmem_cache_destroy(nat_entry_slab);
1802 }