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, LOOKUP_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         if (PageUptodate(page)) {
 203                 unlock_page(page);
 204                 return page;
 205         }
 206
 207         err = f2fs_readpage(sbi, page, dn.data_blkaddr, READ_SYNC);
 208         wait_on_page_locked(page);
 209         if (!PageUptodate(page)) {
 210                 f2fs_put_page(page, 0);
 211                 return ERR_PTR(-EIO);
 212         }
 213         return page;
 214 }
 215
 216 /*
 217  * If it tries to access a hole, return an error.
 218  * Because, the callers, functions in dir.c and GC, should be able to know
 219  * whether this page exists or not.
 220  */
 221 struct page *get_lock_data_page(struct inode *inode, pgoff_t index)
 222 {
 223         struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
 224         struct address_space *mapping = inode->i_mapping;
 225         struct dnode_of_data dn;
 226         struct page *page;
 227         int err;
 228
 229         set_new_dnode(&dn, inode, NULL, NULL, 0);
 230         err = get_dnode_of_data(&dn, index, LOOKUP_NODE);
 231         if (err)
 232                 return ERR_PTR(err);
 233         f2fs_put_dnode(&dn);
 234
 235         if (dn.data_blkaddr == NULL_ADDR)
 236                 return ERR_PTR(-ENOENT);
 237
 238         page = grab_cache_page(mapping, index);
 239         if (!page)
 240                 return ERR_PTR(-ENOMEM);
 241
 242         if (PageUptodate(page))
 243                 return page;
 244
 245         BUG_ON(dn.data_blkaddr == NEW_ADDR);
 246         BUG_ON(dn.data_blkaddr == NULL_ADDR);
 247
 248         err = f2fs_readpage(sbi, page, dn.data_blkaddr, READ_SYNC);
 249         if (err)
 250                 return ERR_PTR(err);
 251
 252         lock_page(page);
 253         if (!PageUptodate(page)) {
 254                 f2fs_put_page(page, 1);
 255                 return ERR_PTR(-EIO);
 256         }
 257         return page;
 258 }
 259
 260 /*
 261  * Caller ensures that this data page is never allocated.
 262  * A new zero-filled data page is allocated in the page cache.
 263  */
 264 struct page *get_new_data_page(struct inode *inode, pgoff_t index,
 265                                                 bool new_i_size)
 266 {
 267         struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
 268         struct address_space *mapping = inode->i_mapping;
 269         struct page *page;
 270         struct dnode_of_data dn;
 271         int err;
 272
 273         set_new_dnode(&dn, inode, NULL, NULL, 0);
 274         err = get_dnode_of_data(&dn, index, ALLOC_NODE);
 275         if (err)
 276                 return ERR_PTR(err);
 277
 278         if (dn.data_blkaddr == NULL_ADDR) {
 279                 if (reserve_new_block(&dn)) {
 280                         f2fs_put_dnode(&dn);
 281                         return ERR_PTR(-ENOSPC);
 282                 }
 283         }
 284         f2fs_put_dnode(&dn);
 285
 286         page = grab_cache_page(mapping, index);
 287         if (!page)
 288                 return ERR_PTR(-ENOMEM);
 289
 290         if (PageUptodate(page))
 291                 return page;
 292
 293         if (dn.data_blkaddr == NEW_ADDR) {
 294                 zero_user_segment(page, 0, PAGE_CACHE_SIZE);
 295                 SetPageUptodate(page);
 296         } else {
 297                 err = f2fs_readpage(sbi, page, dn.data_blkaddr, READ_SYNC);
 298                 if (err)
 299                         return ERR_PTR(err);
 300                 lock_page(page);
 301                 if (!PageUptodate(page)) {
 302                         f2fs_put_page(page, 1);
 303                         return ERR_PTR(-EIO);
 304                 }
 305         }
 306
 307         if (new_i_size &&
 308                 i_size_read(inode) < ((index + 1) << PAGE_CACHE_SHIFT)) {
 309                 i_size_write(inode, ((index + 1) << PAGE_CACHE_SHIFT));
 310                 mark_inode_dirty_sync(inode);
 311         }
 312         return page;
 313 }
 314
 315 static void read_end_io(struct bio *bio, int err)
 316 {
 317         const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
 318         struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
 319
 320         do {
 321                 struct page *page = bvec->bv_page;
 322
 323                 if (--bvec >= bio->bi_io_vec)
 324                         prefetchw(&bvec->bv_page->flags);
 325
 326                 if (uptodate) {
 327                         SetPageUptodate(page);
 328                 } else {
 329                         ClearPageUptodate(page);
 330                         SetPageError(page);
 331                 }
 332                 unlock_page(page);
 333         } while (bvec >= bio->bi_io_vec);
 334         kfree(bio->bi_private);
 335         bio_put(bio);
 336 }
 337
 338 /*
 339  * Fill the locked page with data located in the block address.
 340  * Return unlocked page.
 341  */
 342 int f2fs_readpage(struct f2fs_sb_info *sbi, struct page *page,
 343                                         block_t blk_addr, int type)
 344 {
 345         struct block_device *bdev = sbi->sb->s_bdev;
 346         struct bio *bio;
 347
 348         down_read(&sbi->bio_sem);
 349
 350         /* Allocate a new bio */
 351         bio = f2fs_bio_alloc(bdev, 1);
 352
 353         /* Initialize the bio */
 354         bio->bi_sector = SECTOR_FROM_BLOCK(sbi, blk_addr);
 355         bio->bi_end_io = read_end_io;
 356
 357         if (bio_add_page(bio, page, PAGE_CACHE_SIZE, 0) < PAGE_CACHE_SIZE) {
 358                 kfree(bio->bi_private);
 359                 bio_put(bio);
 360                 up_read(&sbi->bio_sem);
 361                 f2fs_put_page(page, 1);
 362                 return -EFAULT;
 363         }
 364
 365         submit_bio(type, bio);
 366         up_read(&sbi->bio_sem);
 367         return 0;
 368 }
 369
 370 /*
 371  * This function should be used by the data read flow only where it
 372  * does not check the "create" flag that indicates block allocation.
 373  * The reason for this special functionality is to exploit VFS readahead
 374  * mechanism.
 375  */
 376 static int get_data_block_ro(struct inode *inode, sector_t iblock,
 377                         struct buffer_head *bh_result, int create)
 378 {
 379         unsigned int blkbits = inode->i_sb->s_blocksize_bits;
 380         unsigned maxblocks = bh_result->b_size >> blkbits;
 381         struct dnode_of_data dn;
 382         pgoff_t pgofs;
 383         int err;
 384
 385         /* Get the page offset from the block offset(iblock) */
 386         pgofs = (pgoff_t)(iblock >> (PAGE_CACHE_SHIFT - blkbits));
 387
 388         if (check_extent_cache(inode, pgofs, bh_result))
 389                 return 0;
 390
 391         /* When reading holes, we need its node page */
 392         set_new_dnode(&dn, inode, NULL, NULL, 0);
 393         err = get_dnode_of_data(&dn, pgofs, LOOKUP_NODE_RA);
 394         if (err)
 395                 return (err == -ENOENT) ? 0 : err;
 396
 397         /* It does not support data allocation */
 398         BUG_ON(create);
 399
 400         if (dn.data_blkaddr != NEW_ADDR && dn.data_blkaddr != NULL_ADDR) {
 401                 int i;
 402                 unsigned int end_offset;
 403
 404                 end_offset = IS_INODE(dn.node_page) ?
 405                                 ADDRS_PER_INODE :
 406                                 ADDRS_PER_BLOCK;
 407
 408                 clear_buffer_new(bh_result);
 409
 410                 /* Give more consecutive addresses for the read ahead */
 411                 for (i = 0; i < end_offset - dn.ofs_in_node; i++)
 412                         if (((datablock_addr(dn.node_page,
 413                                                         dn.ofs_in_node + i))
 414                                 != (dn.data_blkaddr + i)) || maxblocks == i)
 415                                 break;
 416                 map_bh(bh_result, inode->i_sb, dn.data_blkaddr);
 417                 bh_result->b_size = (i << blkbits);
 418         }
 419         f2fs_put_dnode(&dn);
 420         return 0;
 421 }
 422
 423 static int f2fs_read_data_page(struct file *file, struct page *page)
 424 {
 425         return mpage_readpage(page, get_data_block_ro);
 426 }
 427
 428 static int f2fs_read_data_pages(struct file *file,
 429                         struct address_space *mapping,
 430                         struct list_head *pages, unsigned nr_pages)
 431 {
 432         return mpage_readpages(mapping, pages, nr_pages, get_data_block_ro);
 433 }
 434
 435 int do_write_data_page(struct page *page)
 436 {
 437         struct inode *inode = page->mapping->host;
 438         struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
 439         block_t old_blk_addr, new_blk_addr;
 440         struct dnode_of_data dn;
 441         int err = 0;
 442
 443         set_new_dnode(&dn, inode, NULL, NULL, 0);
 444         err = get_dnode_of_data(&dn, page->index, LOOKUP_NODE);
 445         if (err)
 446                 return err;
 447
 448         old_blk_addr = dn.data_blkaddr;
 449
 450         /* This page is already truncated */
 451         if (old_blk_addr == NULL_ADDR)
 452                 goto out_writepage;
 453
 454         set_page_writeback(page);
 455
 456         /*
 457          * If current allocation needs SSR,
 458          * it had better in-place writes for updated data.
 459          */
 460         if (old_blk_addr != NEW_ADDR && !is_cold_data(page) &&
 461                                 need_inplace_update(inode)) {
 462                 rewrite_data_page(F2FS_SB(inode->i_sb), page,
 463                                                 old_blk_addr);
 464         } else {
 465                 write_data_page(inode, page, &dn,
 466                                 old_blk_addr, &new_blk_addr);
 467                 update_extent_cache(new_blk_addr, &dn);
 468                 F2FS_I(inode)->data_version =
 469                         le64_to_cpu(F2FS_CKPT(sbi)->checkpoint_ver);
 470         }
 471 out_writepage:
 472         f2fs_put_dnode(&dn);
 473         return err;
 474 }
 475
 476 static int f2fs_write_data_page(struct page *page,
 477                                         struct writeback_control *wbc)
 478 {
 479         struct inode *inode = page->mapping->host;
 480         struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
 481         loff_t i_size = i_size_read(inode);
 482         const pgoff_t end_index = ((unsigned long long) i_size)
 483                                                         >> PAGE_CACHE_SHIFT;
 484         unsigned offset;
 485         int err = 0;
 486
 487         if (page->index < end_index)
 488                 goto out;
 489
 490         /*
 491          * If the offset is out-of-range of file size,
 492          * this page does not have to be written to disk.
 493          */
 494         offset = i_size & (PAGE_CACHE_SIZE - 1);
 495         if ((page->index >= end_index + 1) || !offset) {
 496                 if (S_ISDIR(inode->i_mode)) {
 497                         dec_page_count(sbi, F2FS_DIRTY_DENTS);
 498                         inode_dec_dirty_dents(inode);
 499                 }
 500                 goto unlock_out;
 501         }
 502
 503         zero_user_segment(page, offset, PAGE_CACHE_SIZE);
 504 out:
 505         if (sbi->por_doing)
 506                 goto redirty_out;
 507
 508         if (wbc->for_reclaim && !S_ISDIR(inode->i_mode) && !is_cold_data(page))
 509                 goto redirty_out;
 510
 511         mutex_lock_op(sbi, DATA_WRITE);
 512         if (S_ISDIR(inode->i_mode)) {
 513                 dec_page_count(sbi, F2FS_DIRTY_DENTS);
 514                 inode_dec_dirty_dents(inode);
 515         }
 516         err = do_write_data_page(page);
 517         if (err && err != -ENOENT) {
 518                 wbc->pages_skipped++;
 519                 set_page_dirty(page);
 520         }
 521         mutex_unlock_op(sbi, DATA_WRITE);
 522
 523         if (wbc->for_reclaim)
 524                 f2fs_submit_bio(sbi, DATA, true);
 525
 526         if (err == -ENOENT)
 527                 goto unlock_out;
 528
 529         clear_cold_data(page);
 530         unlock_page(page);
 531
 532         if (!wbc->for_reclaim && !S_ISDIR(inode->i_mode))
 533                 f2fs_balance_fs(sbi);
 534         return 0;
 535
 536 unlock_out:
 537         unlock_page(page);
 538         return (err == -ENOENT) ? 0 : err;
 539
 540 redirty_out:
 541         wbc->pages_skipped++;
 542         set_page_dirty(page);
 543         return AOP_WRITEPAGE_ACTIVATE;
 544 }
 545
 546 #define MAX_DESIRED_PAGES_WP    4096
 547
 548 static int __f2fs_writepage(struct page *page, struct writeback_control *wbc,
 549                         void *data)
 550 {
 551         struct address_space *mapping = data;
 552         int ret = mapping->a_ops->writepage(page, wbc);
 553         mapping_set_error(mapping, ret);
 554         return ret;
 555 }
 556
 557 static int f2fs_write_data_pages(struct address_space *mapping,
 558                             struct writeback_control *wbc)
 559 {
 560         struct inode *inode = mapping->host;
 561         struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
 562         int ret;
 563         long excess_nrtw = 0, desired_nrtw;
 564
 565         if (wbc->nr_to_write < MAX_DESIRED_PAGES_WP) {
 566                 desired_nrtw = MAX_DESIRED_PAGES_WP;
 567                 excess_nrtw = desired_nrtw - wbc->nr_to_write;
 568                 wbc->nr_to_write = desired_nrtw;
 569         }
 570
 571         if (!S_ISDIR(inode->i_mode))
 572                 mutex_lock(&sbi->writepages);
 573         ret = write_cache_pages(mapping, wbc, __f2fs_writepage, mapping);
 574         if (!S_ISDIR(inode->i_mode))
 575                 mutex_unlock(&sbi->writepages);
 576         f2fs_submit_bio(sbi, DATA, (wbc->sync_mode == WB_SYNC_ALL));
 577
 578         remove_dirty_dir_inode(inode);
 579
 580         wbc->nr_to_write -= excess_nrtw;
 581         return ret;
 582 }
 583
 584 static int f2fs_write_begin(struct file *file, struct address_space *mapping,
 585                 loff_t pos, unsigned len, unsigned flags,
 586                 struct page **pagep, void **fsdata)
 587 {
 588         struct inode *inode = mapping->host;
 589         struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
 590         struct page *page;
 591         pgoff_t index = ((unsigned long long) pos) >> PAGE_CACHE_SHIFT;
 592         struct dnode_of_data dn;
 593         int err = 0;
 594
 595         /* for nobh_write_end */
 596         *fsdata = NULL;
 597
 598         f2fs_balance_fs(sbi);
 599
 600         page = grab_cache_page_write_begin(mapping, index, flags);
 601         if (!page)
 602                 return -ENOMEM;
 603         *pagep = page;
 604
 605         mutex_lock_op(sbi, DATA_NEW);
 606
 607         set_new_dnode(&dn, inode, NULL, NULL, 0);
 608         err = get_dnode_of_data(&dn, index, ALLOC_NODE);
 609         if (err) {
 610                 mutex_unlock_op(sbi, DATA_NEW);
 611                 f2fs_put_page(page, 1);
 612                 return err;
 613         }
 614
 615         if (dn.data_blkaddr == NULL_ADDR) {
 616                 err = reserve_new_block(&dn);
 617                 if (err) {
 618                         f2fs_put_dnode(&dn);
 619                         mutex_unlock_op(sbi, DATA_NEW);
 620                         f2fs_put_page(page, 1);
 621                         return err;
 622                 }
 623         }
 624         f2fs_put_dnode(&dn);
 625
 626         mutex_unlock_op(sbi, DATA_NEW);
 627
 628         if ((len == PAGE_CACHE_SIZE) || PageUptodate(page))
 629                 return 0;
 630
 631         if ((pos & PAGE_CACHE_MASK) >= i_size_read(inode)) {
 632                 unsigned start = pos & (PAGE_CACHE_SIZE - 1);
 633                 unsigned end = start + len;
 634
 635                 /* Reading beyond i_size is simple: memset to zero */
 636                 zero_user_segments(page, 0, start, end, PAGE_CACHE_SIZE);
 637                 goto out;
 638         }
 639
 640         if (dn.data_blkaddr == NEW_ADDR) {
 641                 zero_user_segment(page, 0, PAGE_CACHE_SIZE);
 642         } else {
 643                 err = f2fs_readpage(sbi, page, dn.data_blkaddr, READ_SYNC);
 644                 if (err)
 645                         return err;
 646                 lock_page(page);
 647                 if (!PageUptodate(page)) {
 648                         f2fs_put_page(page, 1);
 649                         return -EIO;
 650                 }
 651         }
 652 out:
 653         SetPageUptodate(page);
 654         clear_cold_data(page);
 655         return 0;
 656 }
 657
 658 static ssize_t f2fs_direct_IO(int rw, struct kiocb *iocb,
 659                 const struct iovec *iov, loff_t offset, unsigned long nr_segs)
 660 {
 661         struct file *file = iocb->ki_filp;
 662         struct inode *inode = file->f_mapping->host;
 663
 664         if (rw == WRITE)
 665                 return 0;
 666
 667         /* Needs synchronization with the cleaner */
 668         return blockdev_direct_IO(rw, iocb, inode, iov, offset, nr_segs,
 669                                                   get_data_block_ro);
 670 }
 671
 672 static void f2fs_invalidate_data_page(struct page *page, unsigned long offset)
 673 {
 674         struct inode *inode = page->mapping->host;
 675         struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
 676         if (S_ISDIR(inode->i_mode) && PageDirty(page)) {
 677                 dec_page_count(sbi, F2FS_DIRTY_DENTS);
 678                 inode_dec_dirty_dents(inode);
 679         }
 680         ClearPagePrivate(page);
 681 }
 682
 683 static int f2fs_release_data_page(struct page *page, gfp_t wait)
 684 {
 685         ClearPagePrivate(page);
 686         return 0;
 687 }
 688
 689 static int f2fs_set_data_page_dirty(struct page *page)
 690 {
 691         struct address_space *mapping = page->mapping;
 692         struct inode *inode = mapping->host;
 693
 694         SetPageUptodate(page);
 695         if (!PageDirty(page)) {
 696                 __set_page_dirty_nobuffers(page);
 697                 set_dirty_dir_page(inode, page);
 698                 return 1;
 699         }
 700         return 0;
 701 }
 702
 703 static sector_t f2fs_bmap(struct address_space *mapping, sector_t block)
 704 {
 705         return generic_block_bmap(mapping, block, get_data_block_ro);
 706 }
 707
 708 const struct address_space_operations f2fs_dblock_aops = {
 709         .readpage       = f2fs_read_data_page,
 710         .readpages      = f2fs_read_data_pages,
 711         .writepage      = f2fs_write_data_page,
 712         .writepages     = f2fs_write_data_pages,
 713         .write_begin    = f2fs_write_begin,
 714         .write_end      = nobh_write_end,
 715         .set_page_dirty = f2fs_set_data_page_dirty,
 716         .invalidatepage = f2fs_invalidate_data_page,
 717         .releasepage    = f2fs_release_data_page,
 718         .direct_IO      = f2fs_direct_IO,
 719         .bmap           = f2fs_bmap,
 720 };