fs/f2fs/recovery.c

   1 /*
   2  * fs/f2fs/recovery.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 "f2fs.h"
  14 #include "node.h"
  15 #include "segment.h"
  16
  17 /*
  18  * Roll forward recovery scenarios.
  19  *
  20  * [Term] F: fsync_mark, D: dentry_mark
  21  *
  22  * 1. inode(x) | CP | inode(x) | dnode(F)
  23  * -> Update the latest inode(x).
  24  *
  25  * 2. inode(x) | CP | inode(F) | dnode(F)
  26  * -> No problem.
  27  *
  28  * 3. inode(x) | CP | dnode(F) | inode(x)
  29  * -> Recover to the latest dnode(F), and drop the last inode(x)
  30  *
  31  * 4. inode(x) | CP | dnode(F) | inode(F)
  32  * -> No problem.
  33  *
  34  * 5. CP | inode(x) | dnode(F)
  35  * -> The inode(DF) was missing. Should drop this dnode(F).
  36  *
  37  * 6. CP | inode(DF) | dnode(F)
  38  * -> No problem.
  39  *
  40  * 7. CP | dnode(F) | inode(DF)
  41  * -> If f2fs_iget fails, then goto next to find inode(DF).
  42  *
  43  * 8. CP | dnode(F) | inode(x)
  44  * -> If f2fs_iget fails, then goto next to find inode(DF).
  45  *    But it will fail due to no inode(DF).
  46  */
  47
  48 static struct kmem_cache *fsync_entry_slab;
  49
  50 bool f2fs_space_for_roll_forward(struct f2fs_sb_info *sbi)
  51 {
  52         s64 nalloc = percpu_counter_sum_positive(&sbi->alloc_valid_block_count);
  53
  54         if (sbi->last_valid_block_count + nalloc > sbi->user_block_count)
  55                 return false;
  56         return true;
  57 }
  58
  59 static struct fsync_inode_entry *get_fsync_inode(struct list_head *head,
  60                                                                 nid_t ino)
  61 {
  62         struct fsync_inode_entry *entry;
  63
  64         list_for_each_entry(entry, head, list)
  65                 if (entry->inode->i_ino == ino)
  66                         return entry;
  67
  68         return NULL;
  69 }
  70
  71 static struct fsync_inode_entry *add_fsync_inode(struct f2fs_sb_info *sbi,
  72                         struct list_head *head, nid_t ino, bool quota_inode)
  73 {
  74         struct inode *inode;
  75         struct fsync_inode_entry *entry;
  76         int err;
  77
  78         inode = f2fs_iget_retry(sbi->sb, ino);
  79         if (IS_ERR(inode))
  80                 return ERR_CAST(inode);
  81
  82         err = dquot_initialize(inode);
  83         if (err)
  84                 goto err_out;
  85
  86         if (quota_inode) {
  87                 err = dquot_alloc_inode(inode);
  88                 if (err)
  89                         goto err_out;
  90         }
  91
  92         entry = f2fs_kmem_cache_alloc(fsync_entry_slab, GFP_F2FS_ZERO);
  93         entry->inode = inode;
  94         list_add_tail(&entry->list, head);
  95
  96         return entry;
  97 err_out:
  98         iput(inode);
  99         return ERR_PTR(err);
 100 }
 101
 102 static void del_fsync_inode(struct fsync_inode_entry *entry)
 103 {
 104         iput(entry->inode);
 105         list_del(&entry->list);
 106         kmem_cache_free(fsync_entry_slab, entry);
 107 }
 108
 109 static int recover_dentry(struct inode *inode, struct page *ipage,
 110                                                 struct list_head *dir_list)
 111 {
 112         struct f2fs_inode *raw_inode = F2FS_INODE(ipage);
 113         nid_t pino = le32_to_cpu(raw_inode->i_pino);
 114         struct f2fs_dir_entry *de;
 115         struct fscrypt_name fname;
 116         struct page *page;
 117         struct inode *dir, *einode;
 118         struct fsync_inode_entry *entry;
 119         int err = 0;
 120         char *name;
 121
 122         entry = get_fsync_inode(dir_list, pino);
 123         if (!entry) {
 124                 entry = add_fsync_inode(F2FS_I_SB(inode), dir_list,
 125                                                         pino, false);
 126                 if (IS_ERR(entry)) {
 127                         dir = ERR_CAST(entry);
 128                         err = PTR_ERR(entry);
 129                         goto out;
 130                 }
 131         }
 132
 133         dir = entry->inode;
 134
 135         memset(&fname, 0, sizeof(struct fscrypt_name));
 136         fname.disk_name.len = le32_to_cpu(raw_inode->i_namelen);
 137         fname.disk_name.name = raw_inode->i_name;
 138
 139         if (unlikely(fname.disk_name.len > F2FS_NAME_LEN)) {
 140                 WARN_ON(1);
 141                 err = -ENAMETOOLONG;
 142                 goto out;
 143         }
 144 retry:
 145         de = __f2fs_find_entry(dir, &fname, &page);
 146         if (de && inode->i_ino == le32_to_cpu(de->ino))
 147                 goto out_put;
 148
 149         if (de) {
 150                 einode = f2fs_iget_retry(inode->i_sb, le32_to_cpu(de->ino));
 151                 if (IS_ERR(einode)) {
 152                         WARN_ON(1);
 153                         err = PTR_ERR(einode);
 154                         if (err == -ENOENT)
 155                                 err = -EEXIST;
 156                         goto out_put;
 157                 }
 158
 159                 err = dquot_initialize(einode);
 160                 if (err) {
 161                         iput(einode);
 162                         goto out_put;
 163                 }
 164
 165                 err = f2fs_acquire_orphan_inode(F2FS_I_SB(inode));
 166                 if (err) {
 167                         iput(einode);
 168                         goto out_put;
 169                 }
 170                 f2fs_delete_entry(de, page, dir, einode);
 171                 iput(einode);
 172                 goto retry;
 173         } else if (IS_ERR(page)) {
 174                 err = PTR_ERR(page);
 175         } else {
 176                 err = f2fs_add_dentry(dir, &fname, inode,
 177                                         inode->i_ino, inode->i_mode);
 178         }
 179         if (err == -ENOMEM)
 180                 goto retry;
 181         goto out;
 182
 183 out_put:
 184         f2fs_put_page(page, 0);
 185 out:
 186         if (file_enc_name(inode))
 187                 name = "<encrypted>";
 188         else
 189                 name = raw_inode->i_name;
 190         f2fs_msg(inode->i_sb, KERN_NOTICE,
 191                         "%s: ino = %x, name = %s, dir = %lx, err = %d",
 192                         __func__, ino_of_node(ipage), name,
 193                         IS_ERR(dir) ? 0 : dir->i_ino, err);
 194         return err;
 195 }
 196
 197 static void recover_inline_flags(struct inode *inode, struct f2fs_inode *ri)
 198 {
 199         if (ri->i_inline & F2FS_PIN_FILE)
 200                 set_inode_flag(inode, FI_PIN_FILE);
 201         else
 202                 clear_inode_flag(inode, FI_PIN_FILE);
 203         if (ri->i_inline & F2FS_DATA_EXIST)
 204                 set_inode_flag(inode, FI_DATA_EXIST);
 205         else
 206                 clear_inode_flag(inode, FI_DATA_EXIST);
 207 }
 208
 209 static void recover_inode(struct inode *inode, struct page *page)
 210 {
 211         struct f2fs_inode *raw = F2FS_INODE(page);
 212         char *name;
 213
 214         inode->i_mode = le16_to_cpu(raw->i_mode);
 215         f2fs_i_size_write(inode, le64_to_cpu(raw->i_size));
 216         inode->i_atime.tv_sec = le64_to_cpu(raw->i_atime);
 217         inode->i_ctime.tv_sec = le64_to_cpu(raw->i_ctime);
 218         inode->i_mtime.tv_sec = le64_to_cpu(raw->i_mtime);
 219         inode->i_atime.tv_nsec = le32_to_cpu(raw->i_atime_nsec);
 220         inode->i_ctime.tv_nsec = le32_to_cpu(raw->i_ctime_nsec);
 221         inode->i_mtime.tv_nsec = le32_to_cpu(raw->i_mtime_nsec);
 222
 223         F2FS_I(inode)->i_advise = raw->i_advise;
 224
 225         recover_inline_flags(inode, raw);
 226
 227         if (file_enc_name(inode))
 228                 name = "<encrypted>";
 229         else
 230                 name = F2FS_INODE(page)->i_name;
 231
 232         f2fs_msg(inode->i_sb, KERN_NOTICE,
 233                 "recover_inode: ino = %x, name = %s, inline = %x",
 234                         ino_of_node(page), name, raw->i_inline);
 235 }
 236
 237 static int find_fsync_dnodes(struct f2fs_sb_info *sbi, struct list_head *head,
 238                                 bool check_only)
 239 {
 240         struct curseg_info *curseg;
 241         struct page *page = NULL;
 242         block_t blkaddr;
 243         unsigned int loop_cnt = 0;
 244         unsigned int free_blocks = sbi->user_block_count -
 245                                         valid_user_blocks(sbi);
 246         int err = 0;
 247
 248         /* get node pages in the current segment */
 249         curseg = CURSEG_I(sbi, CURSEG_WARM_NODE);
 250         blkaddr = NEXT_FREE_BLKADDR(sbi, curseg);
 251
 252         while (1) {
 253                 struct fsync_inode_entry *entry;
 254
 255                 if (!f2fs_is_valid_meta_blkaddr(sbi, blkaddr, META_POR))
 256                         return 0;
 257
 258                 page = f2fs_get_tmp_page(sbi, blkaddr);
 259
 260                 if (!is_recoverable_dnode(page))
 261                         break;
 262
 263                 if (!is_fsync_dnode(page))
 264                         goto next;
 265
 266                 entry = get_fsync_inode(head, ino_of_node(page));
 267                 if (!entry) {
 268                         bool quota_inode = false;
 269
 270                         if (!check_only &&
 271                                         IS_INODE(page) && is_dent_dnode(page)) {
 272                                 err = f2fs_recover_inode_page(sbi, page);
 273                                 if (err)
 274                                         break;
 275                                 quota_inode = true;
 276                         }
 277
 278                         /*
 279                          * CP | dnode(F) | inode(DF)
 280                          * For this case, we should not give up now.
 281                          */
 282                         entry = add_fsync_inode(sbi, head, ino_of_node(page),
 283                                                                 quota_inode);
 284                         if (IS_ERR(entry)) {
 285                                 err = PTR_ERR(entry);
 286                                 if (err == -ENOENT) {
 287                                         err = 0;
 288                                         goto next;
 289                                 }
 290                                 break;
 291                         }
 292                 }
 293                 entry->blkaddr = blkaddr;
 294
 295                 if (IS_INODE(page) && is_dent_dnode(page))
 296                         entry->last_dentry = blkaddr;
 297 next:
 298                 /* sanity check in order to detect looped node chain */
 299                 if (++loop_cnt >= free_blocks ||
 300                         blkaddr == next_blkaddr_of_node(page)) {
 301                         f2fs_msg(sbi->sb, KERN_NOTICE,
 302                                 "%s: detect looped node chain, "
 303                                 "blkaddr:%u, next:%u",
 304                                 __func__, blkaddr, next_blkaddr_of_node(page));
 305                         err = -EINVAL;
 306                         break;
 307                 }
 308
 309                 /* check next segment */
 310                 blkaddr = next_blkaddr_of_node(page);
 311                 f2fs_put_page(page, 1);
 312
 313                 f2fs_ra_meta_pages_cond(sbi, blkaddr);
 314         }
 315         f2fs_put_page(page, 1);
 316         return err;
 317 }
 318
 319 static void destroy_fsync_dnodes(struct list_head *head)
 320 {
 321         struct fsync_inode_entry *entry, *tmp;
 322
 323         list_for_each_entry_safe(entry, tmp, head, list)
 324                 del_fsync_inode(entry);
 325 }
 326
 327 static int check_index_in_prev_nodes(struct f2fs_sb_info *sbi,
 328                         block_t blkaddr, struct dnode_of_data *dn)
 329 {
 330         struct seg_entry *sentry;
 331         unsigned int segno = GET_SEGNO(sbi, blkaddr);
 332         unsigned short blkoff = GET_BLKOFF_FROM_SEG0(sbi, blkaddr);
 333         struct f2fs_summary_block *sum_node;
 334         struct f2fs_summary sum;
 335         struct page *sum_page, *node_page;
 336         struct dnode_of_data tdn = *dn;
 337         nid_t ino, nid;
 338         struct inode *inode;
 339         unsigned int offset;
 340         block_t bidx;
 341         int i;
 342
 343         sentry = get_seg_entry(sbi, segno);
 344         if (!f2fs_test_bit(blkoff, sentry->cur_valid_map))
 345                 return 0;
 346
 347         /* Get the previous summary */
 348         for (i = CURSEG_HOT_DATA; i <= CURSEG_COLD_DATA; i++) {
 349                 struct curseg_info *curseg = CURSEG_I(sbi, i);
 350                 if (curseg->segno == segno) {
 351                         sum = curseg->sum_blk->entries[blkoff];
 352                         goto got_it;
 353                 }
 354         }
 355
 356         sum_page = f2fs_get_sum_page(sbi, segno);
 357         sum_node = (struct f2fs_summary_block *)page_address(sum_page);
 358         sum = sum_node->entries[blkoff];
 359         f2fs_put_page(sum_page, 1);
 360 got_it:
 361         /* Use the locked dnode page and inode */
 362         nid = le32_to_cpu(sum.nid);
 363         if (dn->inode->i_ino == nid) {
 364                 tdn.nid = nid;
 365                 if (!dn->inode_page_locked)
 366                         lock_page(dn->inode_page);
 367                 tdn.node_page = dn->inode_page;
 368                 tdn.ofs_in_node = le16_to_cpu(sum.ofs_in_node);
 369                 goto truncate_out;
 370         } else if (dn->nid == nid) {
 371                 tdn.ofs_in_node = le16_to_cpu(sum.ofs_in_node);
 372                 goto truncate_out;
 373         }
 374
 375         /* Get the node page */
 376         node_page = f2fs_get_node_page(sbi, nid);
 377         if (IS_ERR(node_page))
 378                 return PTR_ERR(node_page);
 379
 380         offset = ofs_of_node(node_page);
 381         ino = ino_of_node(node_page);
 382         f2fs_put_page(node_page, 1);
 383
 384         if (ino != dn->inode->i_ino) {
 385                 int ret;
 386
 387                 /* Deallocate previous index in the node page */
 388                 inode = f2fs_iget_retry(sbi->sb, ino);
 389                 if (IS_ERR(inode))
 390                         return PTR_ERR(inode);
 391
 392                 ret = dquot_initialize(inode);
 393                 if (ret) {
 394                         iput(inode);
 395                         return ret;
 396                 }
 397         } else {
 398                 inode = dn->inode;
 399         }
 400
 401         bidx = f2fs_start_bidx_of_node(offset, inode) +
 402                                 le16_to_cpu(sum.ofs_in_node);
 403
 404         /*
 405          * if inode page is locked, unlock temporarily, but its reference
 406          * count keeps alive.
 407          */
 408         if (ino == dn->inode->i_ino && dn->inode_page_locked)
 409                 unlock_page(dn->inode_page);
 410
 411         set_new_dnode(&tdn, inode, NULL, NULL, 0);
 412         if (f2fs_get_dnode_of_data(&tdn, bidx, LOOKUP_NODE))
 413                 goto out;
 414
 415         if (tdn.data_blkaddr == blkaddr)
 416                 f2fs_truncate_data_blocks_range(&tdn, 1);
 417
 418         f2fs_put_dnode(&tdn);
 419 out:
 420         if (ino != dn->inode->i_ino)
 421                 iput(inode);
 422         else if (dn->inode_page_locked)
 423                 lock_page(dn->inode_page);
 424         return 0;
 425
 426 truncate_out:
 427         if (datablock_addr(tdn.inode, tdn.node_page,
 428                                         tdn.ofs_in_node) == blkaddr)
 429                 f2fs_truncate_data_blocks_range(&tdn, 1);
 430         if (dn->inode->i_ino == nid && !dn->inode_page_locked)
 431                 unlock_page(dn->inode_page);
 432         return 0;
 433 }
 434
 435 static int do_recover_data(struct f2fs_sb_info *sbi, struct inode *inode,
 436                                         struct page *page)
 437 {
 438         struct dnode_of_data dn;
 439         struct node_info ni;
 440         unsigned int start, end;
 441         int err = 0, recovered = 0;
 442
 443         /* step 1: recover xattr */
 444         if (IS_INODE(page)) {
 445                 f2fs_recover_inline_xattr(inode, page);
 446         } else if (f2fs_has_xattr_block(ofs_of_node(page))) {
 447                 err = f2fs_recover_xattr_data(inode, page);
 448                 if (!err)
 449                         recovered++;
 450                 goto out;
 451         }
 452
 453         /* step 2: recover inline data */
 454         if (f2fs_recover_inline_data(inode, page))
 455                 goto out;
 456
 457         /* step 3: recover data indices */
 458         start = f2fs_start_bidx_of_node(ofs_of_node(page), inode);
 459         end = start + ADDRS_PER_PAGE(page, inode);
 460
 461         set_new_dnode(&dn, inode, NULL, NULL, 0);
 462 retry_dn:
 463         err = f2fs_get_dnode_of_data(&dn, start, ALLOC_NODE);
 464         if (err) {
 465                 if (err == -ENOMEM) {
 466                         congestion_wait(BLK_RW_ASYNC, HZ/50);
 467                         goto retry_dn;
 468                 }
 469                 goto out;
 470         }
 471
 472         f2fs_wait_on_page_writeback(dn.node_page, NODE, true);
 473
 474         f2fs_get_node_info(sbi, dn.nid, &ni);
 475         f2fs_bug_on(sbi, ni.ino != ino_of_node(page));
 476         f2fs_bug_on(sbi, ofs_of_node(dn.node_page) != ofs_of_node(page));
 477
 478         for (; start < end; start++, dn.ofs_in_node++) {
 479                 block_t src, dest;
 480
 481                 src = datablock_addr(dn.inode, dn.node_page, dn.ofs_in_node);
 482                 dest = datablock_addr(dn.inode, page, dn.ofs_in_node);
 483
 484                 /* skip recovering if dest is the same as src */
 485                 if (src == dest)
 486                         continue;
 487
 488                 /* dest is invalid, just invalidate src block */
 489                 if (dest == NULL_ADDR) {
 490                         f2fs_truncate_data_blocks_range(&dn, 1);
 491                         continue;
 492                 }
 493
 494                 if (!file_keep_isize(inode) &&
 495                         (i_size_read(inode) <= ((loff_t)start << PAGE_SHIFT)))
 496                         f2fs_i_size_write(inode,
 497                                 (loff_t)(start + 1) << PAGE_SHIFT);
 498
 499                 /*
 500                  * dest is reserved block, invalidate src block
 501                  * and then reserve one new block in dnode page.
 502                  */
 503                 if (dest == NEW_ADDR) {
 504                         f2fs_truncate_data_blocks_range(&dn, 1);
 505                         f2fs_reserve_new_block(&dn);
 506                         continue;
 507                 }
 508
 509                 /* dest is valid block, try to recover from src to dest */
 510                 if (f2fs_is_valid_meta_blkaddr(sbi, dest, META_POR)) {
 511
 512                         if (src == NULL_ADDR) {
 513                                 err = f2fs_reserve_new_block(&dn);
 514 #ifdef CONFIG_F2FS_FAULT_INJECTION
 515                                 while (err)
 516                                         err = f2fs_reserve_new_block(&dn);
 517 #endif
 518                                 /* We should not get -ENOSPC */
 519                                 f2fs_bug_on(sbi, err);
 520                                 if (err)
 521                                         goto err;
 522                         }
 523 retry_prev:
 524                         /* Check the previous node page having this index */
 525                         err = check_index_in_prev_nodes(sbi, dest, &dn);
 526                         if (err) {
 527                                 if (err == -ENOMEM) {
 528                                         congestion_wait(BLK_RW_ASYNC, HZ/50);
 529                                         goto retry_prev;
 530                                 }
 531                                 goto err;
 532                         }
 533
 534                         /* write dummy data page */
 535                         f2fs_replace_block(sbi, &dn, src, dest,
 536                                                 ni.version, false, false);
 537                         recovered++;
 538                 }
 539         }
 540
 541         copy_node_footer(dn.node_page, page);
 542         fill_node_footer(dn.node_page, dn.nid, ni.ino,
 543                                         ofs_of_node(page), false);
 544         set_page_dirty(dn.node_page);
 545 err:
 546         f2fs_put_dnode(&dn);
 547 out:
 548         f2fs_msg(sbi->sb, KERN_NOTICE,
 549                 "recover_data: ino = %lx (i_size: %s) recovered = %d, err = %d",
 550                 inode->i_ino,
 551                 file_keep_isize(inode) ? "keep" : "recover",
 552                 recovered, err);
 553         return err;
 554 }
 555
 556 static int recover_data(struct f2fs_sb_info *sbi, struct list_head *inode_list,
 557                                                 struct list_head *dir_list)
 558 {
 559         struct curseg_info *curseg;
 560         struct page *page = NULL;
 561         int err = 0;
 562         block_t blkaddr;
 563
 564         /* get node pages in the current segment */
 565         curseg = CURSEG_I(sbi, CURSEG_WARM_NODE);
 566         blkaddr = NEXT_FREE_BLKADDR(sbi, curseg);
 567
 568         while (1) {
 569                 struct fsync_inode_entry *entry;
 570
 571                 if (!f2fs_is_valid_meta_blkaddr(sbi, blkaddr, META_POR))
 572                         break;
 573
 574                 f2fs_ra_meta_pages_cond(sbi, blkaddr);
 575
 576                 page = f2fs_get_tmp_page(sbi, blkaddr);
 577
 578                 if (!is_recoverable_dnode(page)) {
 579                         f2fs_put_page(page, 1);
 580                         break;
 581                 }
 582
 583                 entry = get_fsync_inode(inode_list, ino_of_node(page));
 584                 if (!entry)
 585                         goto next;
 586                 /*
 587                  * inode(x) | CP | inode(x) | dnode(F)
 588                  * In this case, we can lose the latest inode(x).
 589                  * So, call recover_inode for the inode update.
 590                  */
 591                 if (IS_INODE(page))
 592                         recover_inode(entry->inode, page);
 593                 if (entry->last_dentry == blkaddr) {
 594                         err = recover_dentry(entry->inode, page, dir_list);
 595                         if (err) {
 596                                 f2fs_put_page(page, 1);
 597                                 break;
 598                         }
 599                 }
 600                 err = do_recover_data(sbi, entry->inode, page);
 601                 if (err) {
 602                         f2fs_put_page(page, 1);
 603                         break;
 604                 }
 605
 606                 if (entry->blkaddr == blkaddr)
 607                         del_fsync_inode(entry);
 608 next:
 609                 /* check next segment */
 610                 blkaddr = next_blkaddr_of_node(page);
 611                 f2fs_put_page(page, 1);
 612         }
 613         if (!err)
 614                 f2fs_allocate_new_segments(sbi);
 615         return err;
 616 }
 617
 618 int f2fs_recover_fsync_data(struct f2fs_sb_info *sbi, bool check_only)
 619 {
 620         struct list_head inode_list;
 621         struct list_head dir_list;
 622         int err;
 623         int ret = 0;
 624         unsigned long s_flags = sbi->sb->s_flags;
 625         bool need_writecp = false;
 626 #ifdef CONFIG_QUOTA
 627         int quota_enabled;
 628 #endif
 629
 630         if (s_flags & SB_RDONLY) {
 631                 f2fs_msg(sbi->sb, KERN_INFO, "orphan cleanup on readonly fs");
 632                 sbi->sb->s_flags &= ~SB_RDONLY;
 633         }
 634
 635 #ifdef CONFIG_QUOTA
 636         /* Needed for iput() to work correctly and not trash data */
 637         sbi->sb->s_flags |= SB_ACTIVE;
 638         /* Turn on quotas so that they are updated correctly */
 639         quota_enabled = f2fs_enable_quota_files(sbi, s_flags & SB_RDONLY);
 640 #endif
 641
 642         fsync_entry_slab = f2fs_kmem_cache_create("f2fs_fsync_inode_entry",
 643                         sizeof(struct fsync_inode_entry));
 644         if (!fsync_entry_slab) {
 645                 err = -ENOMEM;
 646                 goto out;
 647         }
 648
 649         INIT_LIST_HEAD(&inode_list);
 650         INIT_LIST_HEAD(&dir_list);
 651
 652         /* prevent checkpoint */
 653         mutex_lock(&sbi->cp_mutex);
 654
 655         /* step #1: find fsynced inode numbers */
 656         err = find_fsync_dnodes(sbi, &inode_list, check_only);
 657         if (err || list_empty(&inode_list))
 658                 goto skip;
 659
 660         if (check_only) {
 661                 ret = 1;
 662                 goto skip;
 663         }
 664
 665         need_writecp = true;
 666
 667         /* step #2: recover data */
 668         err = recover_data(sbi, &inode_list, &dir_list);
 669         if (!err)
 670                 f2fs_bug_on(sbi, !list_empty(&inode_list));
 671 skip:
 672         destroy_fsync_dnodes(&inode_list);
 673
 674         /* truncate meta pages to be used by the recovery */
 675         truncate_inode_pages_range(META_MAPPING(sbi),
 676                         (loff_t)MAIN_BLKADDR(sbi) << PAGE_SHIFT, -1);
 677
 678         if (err) {
 679                 truncate_inode_pages_final(NODE_MAPPING(sbi));
 680                 truncate_inode_pages_final(META_MAPPING(sbi));
 681         }
 682
 683         clear_sbi_flag(sbi, SBI_POR_DOING);
 684         mutex_unlock(&sbi->cp_mutex);
 685
 686         /* let's drop all the directory inodes for clean checkpoint */
 687         destroy_fsync_dnodes(&dir_list);
 688
 689         if (!err && need_writecp) {
 690                 struct cp_control cpc = {
 691                         .reason = CP_RECOVERY,
 692                 };
 693                 err = f2fs_write_checkpoint(sbi, &cpc);
 694         }
 695
 696         kmem_cache_destroy(fsync_entry_slab);
 697 out:
 698 #ifdef CONFIG_QUOTA
 699         /* Turn quotas off */
 700         if (quota_enabled)
 701                 f2fs_quota_off_umount(sbi->sb);
 702 #endif
 703         sbi->sb->s_flags = s_flags; /* Restore SB_RDONLY status */
 704
 705         return ret ? ret: err;
 706 }