fs/f2fs/data.c

   1 /*
   2  * fs/f2fs/data.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/buffer_head.h>
  14 #include <linux/mpage.h>
  15 #include <linux/writeback.h>
  16 #include <linux/backing-dev.h>
  17 #include <linux/blkdev.h>
  18 #include <linux/bio.h>
  19 #include <linux/prefetch.h>
  20
  21 #include "f2fs.h"
  22 #include "node.h"
  23 #include "segment.h"
  24
  25 /*
  26  * Lock ordering for the change of data block address:
  27  * ->data_page
  28  *  ->node_page
  29  *    update block addresses in the node page
  30  */
  31 static void __set_data_blkaddr(struct dnode_of_data *dn, block_t new_addr)
  32 {
  33         struct f2fs_node *rn;
  34         __le32 *addr_array;
  35         struct page *node_page = dn->node_page;
  36         unsigned int ofs_in_node = dn->ofs_in_node;
  37
  38         wait_on_page_writeback(node_page);
  39
  40         rn = (struct f2fs_node *)page_address(node_page);
  41
  42         /* Get physical address of data block */
  43         addr_array = blkaddr_in_node(rn);
  44         addr_array[ofs_in_node] = cpu_to_le32(new_addr);
  45         set_page_dirty(node_page);
  46 }
  47
  48 int reserve_new_block(struct dnode_of_data *dn)
  49 {
  50         struct f2fs_sb_info *sbi = F2FS_SB(dn->inode->i_sb);
  51
  52         if (is_inode_flag_set(F2FS_I(dn->inode), FI_NO_ALLOC))
  53                 return -EPERM;
  54         if (!inc_valid_block_count(sbi, dn->inode, 1))
  55                 return -ENOSPC;
  56
  57         __set_data_blkaddr(dn, NEW_ADDR);
  58         dn->data_blkaddr = NEW_ADDR;
  59         sync_inode_page(dn);
  60         return 0;
  61 }
  62
  63 static int check_extent_cache(struct inode *inode, pgoff_t pgofs,
  64                                         struct buffer_head *bh_result)
  65 {
  66         struct f2fs_inode_info *fi = F2FS_I(inode);
  67         struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
  68         pgoff_t start_fofs, end_fofs;
  69         block_t start_blkaddr;
  70
  71         read_lock(&fi->ext.ext_lock);
  72         if (fi->ext.len == 0) {
  73                 read_unlock(&fi->ext.ext_lock);
  74                 return 0;
  75         }
  76
  77         sbi->total_hit_ext++;
  78         start_fofs = fi->ext.fofs;
  79         end_fofs = fi->ext.fofs + fi->ext.len - 1;
  80         start_blkaddr = fi->ext.blk_addr;
  81
  82         if (pgofs >= start_fofs && pgofs <= end_fofs) {
  83                 unsigned int blkbits = inode->i_sb->s_blocksize_bits;
  84                 size_t count;
  85
  86                 clear_buffer_new(bh_result);
  87                 map_bh(bh_result, inode->i_sb,
  88                                 start_blkaddr + pgofs - start_fofs);
  89                 count = end_fofs - pgofs + 1;
  90                 if (count < (UINT_MAX >> blkbits))
  91                         bh_result->b_size = (count << blkbits);
  92                 else
  93                         bh_result->b_size = UINT_MAX;
  94
  95                 sbi->read_hit_ext++;
  96                 read_unlock(&fi->ext.ext_lock);
  97                 return 1;
  98         }
  99         read_unlock(&fi->ext.ext_lock);
 100         return 0;
 101 }
 102
 103 void update_extent_cache(block_t blk_addr, struct dnode_of_data *dn)
 104 {
 105         struct f2fs_inode_info *fi = F2FS_I(dn->inode);
 106         pgoff_t fofs, start_fofs, end_fofs;
 107         block_t start_blkaddr, end_blkaddr;
 108
 109         BUG_ON(blk_addr == NEW_ADDR);
 110         fofs = start_bidx_of_node(ofs_of_node(dn->node_page)) + dn->ofs_in_node;
 111
 112         /* Update the page address in the parent node */
 113         __set_data_blkaddr(dn, blk_addr);
 114
 115         write_lock(&fi->ext.ext_lock);
 116
 117         start_fofs = fi->ext.fofs;
 118         end_fofs = fi->ext.fofs + fi->ext.len - 1;
 119         start_blkaddr = fi->ext.blk_addr;
 120         end_blkaddr = fi->ext.blk_addr + fi->ext.len - 1;
 121
 122         /* Drop and initialize the matched extent */
 123         if (fi->ext.len == 1 && fofs == start_fofs)
 124                 fi->ext.len = 0;
 125
 126         /* Initial extent */
 127         if (fi->ext.len == 0) {
 128                 if (blk_addr != NULL_ADDR) {
 129                         fi->ext.fofs = fofs;
 130                         fi->ext.blk_addr = blk_addr;
 131                         fi->ext.len = 1;
 132                 }
 133                 goto end_update;
 134         }
 135
 136         /* Frone merge */
 137         if (fofs == start_fofs - 1 && blk_addr == start_blkaddr - 1) {
 138                 fi->ext.fofs--;
 139                 fi->ext.blk_addr--;
 140                 fi->ext.len++;
 141                 goto end_update;
 142         }
 143
 144         /* Back merge */
 145         if (fofs == end_fofs + 1 && blk_addr == end_blkaddr + 1) {
 146                 fi->ext.len++;
 147                 goto end_update;
 148         }
 149
 150         /* Split the existing extent */
 151         if (fi->ext.len > 1 &&
 152                 fofs >= start_fofs && fofs <= end_fofs) {
 153                 if ((end_fofs - fofs) < (fi->ext.len >> 1)) {
 154                         fi->ext.len = fofs - start_fofs;
 155                 } else {
 156                         fi->ext.fofs = fofs + 1;
 157                         fi->ext.blk_addr = start_blkaddr +
 158                                         fofs - start_fofs + 1;
 159                         fi->ext.len -= fofs - start_fofs + 1;
 160                 }
 161                 goto end_update;
 162         }
 163         write_unlock(&fi->ext.ext_lock);
 164         return;
 165
 166 end_update:
 167         write_unlock(&fi->ext.ext_lock);
 168         sync_inode_page(dn);
 169         return;
 170 }
 171
 172 struct page *find_data_page(struct inode *inode, pgoff_t index)
 173 {
 174         struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
 175         struct address_space *mapping = inode->i_mapping;
 176         struct dnode_of_data dn;
 177         struct page *page;
 178         int err;
 179
 180         page = find_get_page(mapping, index);
 181         if (page && PageUptodate(page))
 182                 return page;
 183         f2fs_put_page(page, 0);
 184
 185         set_new_dnode(&dn, inode, NULL, NULL, 0);
 186         err = get_dnode_of_data(&dn, index, RDONLY_NODE);
 187         if (err)
 188                 return ERR_PTR(err);
 189         f2fs_put_dnode(&dn);
 190
 191         if (dn.data_blkaddr == NULL_ADDR)
 192                 return ERR_PTR(-ENOENT);
 193
 194         /* By fallocate(), there is no cached page, but with NEW_ADDR */
 195         if (dn.data_blkaddr == NEW_ADDR)
 196                 return ERR_PTR(-EINVAL);
 197
 198         page = grab_cache_page(mapping, index);
 199         if (!page)
 200                 return ERR_PTR(-ENOMEM);
 201
 202         err = f2fs_readpage(sbi, page, dn.data_blkaddr, READ_SYNC);
 203         if (err) {
 204                 f2fs_put_page(page, 1);
 205                 return ERR_PTR(err);
 206         }
 207         unlock_page(page);
 208         return page;
 209 }
 210
 211 /*
 212  * If it tries to access a hole, return an error.
 213  * Because, the callers, functions in dir.c and GC, should be able to know
 214  * whether this page exists or not.
 215  */
 216 struct page *get_lock_data_page(struct inode *inode, pgoff_t index)
 217 {
 218         struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
 219         struct address_space *mapping = inode->i_mapping;
 220         struct dnode_of_data dn;
 221         struct page *page;
 222         int err;
 223
 224         set_new_dnode(&dn, inode, NULL, NULL, 0);
 225         err = get_dnode_of_data(&dn, index, RDONLY_NODE);
 226         if (err)
 227                 return ERR_PTR(err);
 228         f2fs_put_dnode(&dn);
 229
 230         if (dn.data_blkaddr == NULL_ADDR)
 231                 return ERR_PTR(-ENOENT);
 232
 233         page = grab_cache_page(mapping, index);
 234         if (!page)
 235                 return ERR_PTR(-ENOMEM);
 236
 237         if (PageUptodate(page))
 238                 return page;
 239
 240         BUG_ON(dn.data_blkaddr == NEW_ADDR);
 241         BUG_ON(dn.data_blkaddr == NULL_ADDR);
 242
 243         err = f2fs_readpage(sbi, page, dn.data_blkaddr, READ_SYNC);
 244         if (err) {
 245                 f2fs_put_page(page, 1);
 246                 return ERR_PTR(err);
 247         }
 248         return page;
 249 }
 250
 251 /*
 252  * Caller ensures that this data page is never allocated.
 253  * A new zero-filled data page is allocated in the page cache.
 254  */
 255 struct page *get_new_data_page(struct inode *inode, pgoff_t index,
 256                                                 bool new_i_size)
 257 {
 258         struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
 259         struct address_space *mapping = inode->i_mapping;
 260         struct page *page;
 261         struct dnode_of_data dn;
 262         int err;
 263
 264         set_new_dnode(&dn, inode, NULL, NULL, 0);
 265         err = get_dnode_of_data(&dn, index, 0);
 266         if (err)
 267                 return ERR_PTR(err);
 268
 269         if (dn.data_blkaddr == NULL_ADDR) {
 270                 if (reserve_new_block(&dn)) {
 271                         f2fs_put_dnode(&dn);
 272                         return ERR_PTR(-ENOSPC);
 273                 }
 274         }
 275         f2fs_put_dnode(&dn);
 276
 277         page = grab_cache_page(mapping, index);
 278         if (!page)
 279                 return ERR_PTR(-ENOMEM);
 280
 281         if (PageUptodate(page))
 282                 return page;
 283
 284         if (dn.data_blkaddr == NEW_ADDR) {
 285                 zero_user_segment(page, 0, PAGE_CACHE_SIZE);
 286         } else {
 287                 err = f2fs_readpage(sbi, page, dn.data_blkaddr, READ_SYNC);
 288                 if (err) {
 289                         f2fs_put_page(page, 1);
 290                         return ERR_PTR(err);
 291                 }
 292         }
 293         SetPageUptodate(page);
 294
 295         if (new_i_size &&
 296                 i_size_read(inode) < ((index + 1) << PAGE_CACHE_SHIFT)) {
 297                 i_size_write(inode, ((index + 1) << PAGE_CACHE_SHIFT));
 298                 mark_inode_dirty_sync(inode);
 299         }
 300         return page;
 301 }
 302
 303 static void read_end_io(struct bio *bio, int err)
 304 {
 305         const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
 306         struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
 307
 308         do {
 309                 struct page *page = bvec->bv_page;
 310
 311                 if (--bvec >= bio->bi_io_vec)
 312                         prefetchw(&bvec->bv_page->flags);
 313
 314                 if (uptodate) {
 315                         SetPageUptodate(page);
 316                 } else {
 317                         ClearPageUptodate(page);
 318                         SetPageError(page);
 319                 }
 320                 unlock_page(page);
 321         } while (bvec >= bio->bi_io_vec);
 322         kfree(bio->bi_private);
 323         bio_put(bio);
 324 }
 325
 326 /*
 327  * Fill the locked page with data located in the block address.
 328  * Read operation is synchronous, and caller must unlock the page.
 329  */
 330 int f2fs_readpage(struct f2fs_sb_info *sbi, struct page *page,
 331                                         block_t blk_addr, int type)
 332 {
 333         struct block_device *bdev = sbi->sb->s_bdev;
 334         bool sync = (type == READ_SYNC);
 335         struct bio *bio;
 336
 337         /* This page can be already read by other threads */
 338         if (PageUptodate(page)) {
 339                 if (!sync)
 340                         unlock_page(page);
 341                 return 0;
 342         }
 343
 344         down_read(&sbi->bio_sem);
 345
 346         /* Allocate a new bio */
 347         bio = f2fs_bio_alloc(bdev, 1);
 348
 349         /* Initialize the bio */
 350         bio->bi_sector = SECTOR_FROM_BLOCK(sbi, blk_addr);
 351         bio->bi_end_io = read_end_io;
 352
 353         if (bio_add_page(bio, page, PAGE_CACHE_SIZE, 0) < PAGE_CACHE_SIZE) {
 354                 kfree(bio->bi_private);
 355                 bio_put(bio);
 356                 up_read(&sbi->bio_sem);
 357                 return -EFAULT;
 358         }
 359
 360         submit_bio(type, bio);
 361         up_read(&sbi->bio_sem);
 362
 363         /* wait for read completion if sync */
 364         if (sync) {
 365                 lock_page(page);
 366                 if (PageError(page))
 367                         return -EIO;
 368         }
 369         return 0;
 370 }
 371
 372 /*
 373  * This function should be used by the data read flow only where it
 374  * does not check the "create" flag that indicates block allocation.
 375  * The reason for this special functionality is to exploit VFS readahead
 376  * mechanism.
 377  */
 378 static int get_data_block_ro(struct inode *inode, sector_t iblock,
 379                         struct buffer_head *bh_result, int create)
 380 {
 381         unsigned int blkbits = inode->i_sb->s_blocksize_bits;
 382         unsigned maxblocks = bh_result->b_size >> blkbits;
 383         struct dnode_of_data dn;
 384         pgoff_t pgofs;
 385         int err;
 386
 387         /* Get the page offset from the block offset(iblock) */
 388         pgofs = (pgoff_t)(iblock >> (PAGE_CACHE_SHIFT - blkbits));
 389
 390         if (check_extent_cache(inode, pgofs, bh_result))
 391                 return 0;
 392
 393         /* When reading holes, we need its node page */
 394         set_new_dnode(&dn, inode, NULL, NULL, 0);
 395         err = get_dnode_of_data(&dn, pgofs, RDONLY_NODE);
 396         if (err)
 397                 return (err == -ENOENT) ? 0 : err;
 398
 399         /* It does not support data allocation */
 400         BUG_ON(create);
 401
 402         if (dn.data_blkaddr != NEW_ADDR && dn.data_blkaddr != NULL_ADDR) {
 403                 int i;
 404                 unsigned int end_offset;
 405
 406                 end_offset = IS_INODE(dn.node_page) ?
 407                                 ADDRS_PER_INODE :
 408                                 ADDRS_PER_BLOCK;
 409
 410                 clear_buffer_new(bh_result);
 411
 412                 /* Give more consecutive addresses for the read ahead */
 413                 for (i = 0; i < end_offset - dn.ofs_in_node; i++)
 414                         if (((datablock_addr(dn.node_page,
 415                                                         dn.ofs_in_node + i))
 416                                 != (dn.data_blkaddr + i)) || maxblocks == i)
 417                                 break;
 418                 map_bh(bh_result, inode->i_sb, dn.data_blkaddr);
 419                 bh_result->b_size = (i << blkbits);
 420         }
 421         f2fs_put_dnode(&dn);
 422         return 0;
 423 }
 424
 425 static int f2fs_read_data_page(struct file *file, struct page *page)
 426 {
 427         return mpage_readpage(page, get_data_block_ro);
 428 }
 429
 430 static int f2fs_read_data_pages(struct file *file,
 431                         struct address_space *mapping,
 432                         struct list_head *pages, unsigned nr_pages)
 433 {
 434         return mpage_readpages(mapping, pages, nr_pages, get_data_block_ro);
 435 }
 436
 437 int do_write_data_page(struct page *page)
 438 {
 439         struct inode *inode = page->mapping->host;
 440         struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
 441         block_t old_blk_addr, new_blk_addr;
 442         struct dnode_of_data dn;
 443         int err = 0;
 444
 445         set_new_dnode(&dn, inode, NULL, NULL, 0);
 446         err = get_dnode_of_data(&dn, page->index, RDONLY_NODE);
 447         if (err)
 448                 return err;
 449
 450         old_blk_addr = dn.data_blkaddr;
 451
 452         /* This page is already truncated */
 453         if (old_blk_addr == NULL_ADDR)
 454                 goto out_writepage;
 455
 456         set_page_writeback(page);
 457
 458         /*
 459          * If current allocation needs SSR,
 460          * it had better in-place writes for updated data.
 461          */
 462         if (old_blk_addr != NEW_ADDR && !is_cold_data(page) &&
 463                                 need_inplace_update(inode)) {
 464                 rewrite_data_page(F2FS_SB(inode->i_sb), page,
 465                                                 old_blk_addr);
 466         } else {
 467                 write_data_page(inode, page, &dn,
 468                                 old_blk_addr, &new_blk_addr);
 469                 update_extent_cache(new_blk_addr, &dn);
 470                 F2FS_I(inode)->data_version =
 471                         le64_to_cpu(F2FS_CKPT(sbi)->checkpoint_ver);
 472         }
 473 out_writepage:
 474         f2fs_put_dnode(&dn);
 475         return err;
 476 }
 477
 478 static int f2fs_write_data_page(struct page *page,
 479                                         struct writeback_control *wbc)
 480 {
 481         struct inode *inode = page->mapping->host;
 482         struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
 483         loff_t i_size = i_size_read(inode);
 484         const pgoff_t end_index = ((unsigned long long) i_size)
 485                                                         >> PAGE_CACHE_SHIFT;
 486         unsigned offset;
 487         int err = 0;
 488
 489         if (page->index < end_index)
 490                 goto out;
 491
 492         /*
 493          * If the offset is out-of-range of file size,
 494          * this page does not have to be written to disk.
 495          */
 496         offset = i_size & (PAGE_CACHE_SIZE - 1);
 497         if ((page->index >= end_index + 1) || !offset) {
 498                 if (S_ISDIR(inode->i_mode)) {
 499                         dec_page_count(sbi, F2FS_DIRTY_DENTS);
 500                         inode_dec_dirty_dents(inode);
 501                 }
 502                 goto unlock_out;
 503         }
 504
 505         zero_user_segment(page, offset, PAGE_CACHE_SIZE);
 506 out:
 507         if (sbi->por_doing)
 508                 goto redirty_out;
 509
 510         if (wbc->for_reclaim && !S_ISDIR(inode->i_mode) && !is_cold_data(page))
 511                 goto redirty_out;
 512
 513         mutex_lock_op(sbi, DATA_WRITE);
 514         if (S_ISDIR(inode->i_mode)) {
 515                 dec_page_count(sbi, F2FS_DIRTY_DENTS);
 516                 inode_dec_dirty_dents(inode);
 517         }
 518         err = do_write_data_page(page);
 519         if (err && err != -ENOENT) {
 520                 wbc->pages_skipped++;
 521                 set_page_dirty(page);
 522         }
 523         mutex_unlock_op(sbi, DATA_WRITE);
 524
 525         if (wbc->for_reclaim)
 526                 f2fs_submit_bio(sbi, DATA, true);
 527
 528         if (err == -ENOENT)
 529                 goto unlock_out;
 530
 531         clear_cold_data(page);
 532         unlock_page(page);
 533
 534         if (!wbc->for_reclaim && !S_ISDIR(inode->i_mode))
 535                 f2fs_balance_fs(sbi);
 536         return 0;
 537
 538 unlock_out:
 539         unlock_page(page);
 540         return (err == -ENOENT) ? 0 : err;
 541
 542 redirty_out:
 543         wbc->pages_skipped++;
 544         set_page_dirty(page);
 545         return AOP_WRITEPAGE_ACTIVATE;
 546 }
 547
 548 #define MAX_DESIRED_PAGES_WP    4096
 549
 550 static int __f2fs_writepage(struct page *page, struct writeback_control *wbc,
 551                         void *data)
 552 {
 553         struct address_space *mapping = data;
 554         int ret = mapping->a_ops->writepage(page, wbc);
 555         mapping_set_error(mapping, ret);
 556         return ret;
 557 }
 558
 559 static int f2fs_write_data_pages(struct address_space *mapping,
 560                             struct writeback_control *wbc)
 561 {
 562         struct inode *inode = mapping->host;
 563         struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
 564         int ret;
 565         long excess_nrtw = 0, desired_nrtw;
 566
 567         if (wbc->nr_to_write < MAX_DESIRED_PAGES_WP) {
 568                 desired_nrtw = MAX_DESIRED_PAGES_WP;
 569                 excess_nrtw = desired_nrtw - wbc->nr_to_write;
 570                 wbc->nr_to_write = desired_nrtw;
 571         }
 572
 573         if (!S_ISDIR(inode->i_mode))
 574                 mutex_lock(&sbi->writepages);
 575         ret = write_cache_pages(mapping, wbc, __f2fs_writepage, mapping);
 576         if (!S_ISDIR(inode->i_mode))
 577                 mutex_unlock(&sbi->writepages);
 578         f2fs_submit_bio(sbi, DATA, (wbc->sync_mode == WB_SYNC_ALL));
 579
 580         remove_dirty_dir_inode(inode);
 581
 582         wbc->nr_to_write -= excess_nrtw;
 583         return ret;
 584 }
 585
 586 static int f2fs_write_begin(struct file *file, struct address_space *mapping,
 587                 loff_t pos, unsigned len, unsigned flags,
 588                 struct page **pagep, void **fsdata)
 589 {
 590         struct inode *inode = mapping->host;
 591         struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
 592         struct page *page;
 593         pgoff_t index = ((unsigned long long) pos) >> PAGE_CACHE_SHIFT;
 594         struct dnode_of_data dn;
 595         int err = 0;
 596
 597         /* for nobh_write_end */
 598         *fsdata = NULL;
 599
 600         f2fs_balance_fs(sbi);
 601
 602         page = grab_cache_page_write_begin(mapping, index, flags);
 603         if (!page)
 604                 return -ENOMEM;
 605         *pagep = page;
 606
 607         mutex_lock_op(sbi, DATA_NEW);
 608
 609         set_new_dnode(&dn, inode, NULL, NULL, 0);
 610         err = get_dnode_of_data(&dn, index, 0);
 611         if (err) {
 612                 mutex_unlock_op(sbi, DATA_NEW);
 613                 f2fs_put_page(page, 1);
 614                 return err;
 615         }
 616
 617         if (dn.data_blkaddr == NULL_ADDR) {
 618                 err = reserve_new_block(&dn);
 619                 if (err) {
 620                         f2fs_put_dnode(&dn);
 621                         mutex_unlock_op(sbi, DATA_NEW);
 622                         f2fs_put_page(page, 1);
 623                         return err;
 624                 }
 625         }
 626         f2fs_put_dnode(&dn);
 627
 628         mutex_unlock_op(sbi, DATA_NEW);
 629
 630         if ((len == PAGE_CACHE_SIZE) || PageUptodate(page))
 631                 return 0;
 632
 633         if ((pos & PAGE_CACHE_MASK) >= i_size_read(inode)) {
 634                 unsigned start = pos & (PAGE_CACHE_SIZE - 1);
 635                 unsigned end = start + len;
 636
 637                 /* Reading beyond i_size is simple: memset to zero */
 638                 zero_user_segments(page, 0, start, end, PAGE_CACHE_SIZE);
 639                 return 0;
 640         }
 641
 642         if (dn.data_blkaddr == NEW_ADDR) {
 643                 zero_user_segment(page, 0, PAGE_CACHE_SIZE);
 644         } else {
 645                 err = f2fs_readpage(sbi, page, dn.data_blkaddr, READ_SYNC);
 646                 if (err) {
 647                         f2fs_put_page(page, 1);
 648                         return err;
 649                 }
 650         }
 651         SetPageUptodate(page);
 652         clear_cold_data(page);
 653         return 0;
 654 }
 655
 656 static ssize_t f2fs_direct_IO(int rw, struct kiocb *iocb,
 657                 const struct iovec *iov, loff_t offset, unsigned long nr_segs)
 658 {
 659         struct file *file = iocb->ki_filp;
 660         struct inode *inode = file->f_mapping->host;
 661
 662         if (rw == WRITE)
 663                 return 0;
 664
 665         /* Needs synchronization with the cleaner */
 666         return blockdev_direct_IO(rw, iocb, inode, iov, offset, nr_segs,
 667                                                   get_data_block_ro);
 668 }
 669
 670 static void f2fs_invalidate_data_page(struct page *page, unsigned long offset)
 671 {
 672         struct inode *inode = page->mapping->host;
 673         struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
 674         if (S_ISDIR(inode->i_mode) && PageDirty(page)) {
 675                 dec_page_count(sbi, F2FS_DIRTY_DENTS);
 676                 inode_dec_dirty_dents(inode);
 677         }
 678         ClearPagePrivate(page);
 679 }
 680
 681 static int f2fs_release_data_page(struct page *page, gfp_t wait)
 682 {
 683         ClearPagePrivate(page);
 684         return 0;
 685 }
 686
 687 static int f2fs_set_data_page_dirty(struct page *page)
 688 {
 689         struct address_space *mapping = page->mapping;
 690         struct inode *inode = mapping->host;
 691
 692         SetPageUptodate(page);
 693         if (!PageDirty(page)) {
 694                 __set_page_dirty_nobuffers(page);
 695                 set_dirty_dir_page(inode, page);
 696                 return 1;
 697         }
 698         return 0;
 699 }
 700
 701 static sector_t f2fs_bmap(struct address_space *mapping, sector_t block)
 702 {
 703         return generic_block_bmap(mapping, block, get_data_block_ro);
 704 }
 705
 706 const struct address_space_operations f2fs_dblock_aops = {
 707         .readpage       = f2fs_read_data_page,
 708         .readpages      = f2fs_read_data_pages,
 709         .writepage      = f2fs_write_data_page,
 710         .writepages     = f2fs_write_data_pages,
 711         .write_begin    = f2fs_write_begin,
 712         .write_end      = nobh_write_end,
 713         .set_page_dirty = f2fs_set_data_page_dirty,
 714         .invalidatepage = f2fs_invalidate_data_page,
 715         .releasepage    = f2fs_release_data_page,
 716         .direct_IO      = f2fs_direct_IO,
 717         .bmap           = f2fs_bmap,
 718 };