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