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/aio.h> 16 #include <linux/writeback.h> 17 #include <linux/backing-dev.h> 18 #include <linux/blkdev.h> 19 #include <linux/bio.h> 20 #include <linux/prefetch.h> 21 22 #include "f2fs.h" 23 #include "node.h" 24 #include "segment.h" 25 #include <trace/events/f2fs.h> 26 27 /* 28 * Lock ordering for the change of data block address: 29 * ->data_page 30 * ->node_page 31 * update block addresses in the node page 32 */ 33 static void __set_data_blkaddr(struct dnode_of_data *dn, block_t new_addr) 34 { 35 struct f2fs_node *rn; 36 __le32 *addr_array; 37 struct page *node_page = dn->node_page; 38 unsigned int ofs_in_node = dn->ofs_in_node; 39 40 f2fs_wait_on_page_writeback(node_page, NODE, false); 41 42 rn = F2FS_NODE(node_page); 43 44 /* Get physical address of data block */ 45 addr_array = blkaddr_in_node(rn); 46 addr_array[ofs_in_node] = cpu_to_le32(new_addr); 47 set_page_dirty(node_page); 48 } 49 50 int reserve_new_block(struct dnode_of_data *dn) 51 { 52 struct f2fs_sb_info *sbi = F2FS_SB(dn->inode->i_sb); 53 54 if (is_inode_flag_set(F2FS_I(dn->inode), FI_NO_ALLOC)) 55 return -EPERM; 56 if (!inc_valid_block_count(sbi, dn->inode, 1)) 57 return -ENOSPC; 58 59 trace_f2fs_reserve_new_block(dn->inode, dn->nid, dn->ofs_in_node); 60 61 __set_data_blkaddr(dn, NEW_ADDR); 62 dn->data_blkaddr = NEW_ADDR; 63 sync_inode_page(dn); 64 return 0; 65 } 66 67 static int check_extent_cache(struct inode *inode, pgoff_t pgofs, 68 struct buffer_head *bh_result) 69 { 70 struct f2fs_inode_info *fi = F2FS_I(inode); 71 pgoff_t start_fofs, end_fofs; 72 block_t start_blkaddr; 73 74 read_lock(&fi->ext.ext_lock); 75 if (fi->ext.len == 0) { 76 read_unlock(&fi->ext.ext_lock); 77 return 0; 78 } 79 80 stat_inc_total_hit(inode->i_sb); 81 82 start_fofs = fi->ext.fofs; 83 end_fofs = fi->ext.fofs + fi->ext.len - 1; 84 start_blkaddr = fi->ext.blk_addr; 85 86 if (pgofs >= start_fofs && pgofs <= end_fofs) { 87 unsigned int blkbits = inode->i_sb->s_blocksize_bits; 88 size_t count; 89 90 clear_buffer_new(bh_result); 91 map_bh(bh_result, inode->i_sb, 92 start_blkaddr + pgofs - start_fofs); 93 count = end_fofs - pgofs + 1; 94 if (count < (UINT_MAX >> blkbits)) 95 bh_result->b_size = (count << blkbits); 96 else 97 bh_result->b_size = UINT_MAX; 98 99 stat_inc_read_hit(inode->i_sb); 100 read_unlock(&fi->ext.ext_lock); 101 return 1; 102 } 103 read_unlock(&fi->ext.ext_lock); 104 return 0; 105 } 106 107 void update_extent_cache(block_t blk_addr, struct dnode_of_data *dn) 108 { 109 struct f2fs_inode_info *fi = F2FS_I(dn->inode); 110 pgoff_t fofs, start_fofs, end_fofs; 111 block_t start_blkaddr, end_blkaddr; 112 113 f2fs_bug_on(blk_addr == NEW_ADDR); 114 fofs = start_bidx_of_node(ofs_of_node(dn->node_page), fi) + 115 dn->ofs_in_node; 116 117 /* Update the page address in the parent node */ 118 __set_data_blkaddr(dn, blk_addr); 119 120 write_lock(&fi->ext.ext_lock); 121 122 start_fofs = fi->ext.fofs; 123 end_fofs = fi->ext.fofs + fi->ext.len - 1; 124 start_blkaddr = fi->ext.blk_addr; 125 end_blkaddr = fi->ext.blk_addr + fi->ext.len - 1; 126 127 /* Drop and initialize the matched extent */ 128 if (fi->ext.len == 1 && fofs == start_fofs) 129 fi->ext.len = 0; 130 131 /* Initial extent */ 132 if (fi->ext.len == 0) { 133 if (blk_addr != NULL_ADDR) { 134 fi->ext.fofs = fofs; 135 fi->ext.blk_addr = blk_addr; 136 fi->ext.len = 1; 137 } 138 goto end_update; 139 } 140 141 /* Front merge */ 142 if (fofs == start_fofs - 1 && blk_addr == start_blkaddr - 1) { 143 fi->ext.fofs--; 144 fi->ext.blk_addr--; 145 fi->ext.len++; 146 goto end_update; 147 } 148 149 /* Back merge */ 150 if (fofs == end_fofs + 1 && blk_addr == end_blkaddr + 1) { 151 fi->ext.len++; 152 goto end_update; 153 } 154 155 /* Split the existing extent */ 156 if (fi->ext.len > 1 && 157 fofs >= start_fofs && fofs <= end_fofs) { 158 if ((end_fofs - fofs) < (fi->ext.len >> 1)) { 159 fi->ext.len = fofs - start_fofs; 160 } else { 161 fi->ext.fofs = fofs + 1; 162 fi->ext.blk_addr = start_blkaddr + 163 fofs - start_fofs + 1; 164 fi->ext.len -= fofs - start_fofs + 1; 165 } 166 goto end_update; 167 } 168 write_unlock(&fi->ext.ext_lock); 169 return; 170 171 end_update: 172 write_unlock(&fi->ext.ext_lock); 173 sync_inode_page(dn); 174 } 175 176 struct page *find_data_page(struct inode *inode, pgoff_t index, bool sync) 177 { 178 struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb); 179 struct address_space *mapping = inode->i_mapping; 180 struct dnode_of_data dn; 181 struct page *page; 182 int err; 183 184 page = find_get_page(mapping, index); 185 if (page && PageUptodate(page)) 186 return page; 187 f2fs_put_page(page, 0); 188 189 set_new_dnode(&dn, inode, NULL, NULL, 0); 190 err = get_dnode_of_data(&dn, index, LOOKUP_NODE); 191 if (err) 192 return ERR_PTR(err); 193 f2fs_put_dnode(&dn); 194 195 if (dn.data_blkaddr == NULL_ADDR) 196 return ERR_PTR(-ENOENT); 197 198 /* By fallocate(), there is no cached page, but with NEW_ADDR */ 199 if (dn.data_blkaddr == NEW_ADDR) 200 return ERR_PTR(-EINVAL); 201 202 page = grab_cache_page_write_begin(mapping, index, AOP_FLAG_NOFS); 203 if (!page) 204 return ERR_PTR(-ENOMEM); 205 206 if (PageUptodate(page)) { 207 unlock_page(page); 208 return page; 209 } 210 211 err = f2fs_readpage(sbi, page, dn.data_blkaddr, 212 sync ? READ_SYNC : READA); 213 if (sync) { 214 wait_on_page_locked(page); 215 if (!PageUptodate(page)) { 216 f2fs_put_page(page, 0); 217 return ERR_PTR(-EIO); 218 } 219 } 220 return page; 221 } 222 223 /* 224 * If it tries to access a hole, return an error. 225 * Because, the callers, functions in dir.c and GC, should be able to know 226 * whether this page exists or not. 227 */ 228 struct page *get_lock_data_page(struct inode *inode, pgoff_t index) 229 { 230 struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb); 231 struct address_space *mapping = inode->i_mapping; 232 struct dnode_of_data dn; 233 struct page *page; 234 int err; 235 236 repeat: 237 page = grab_cache_page_write_begin(mapping, index, AOP_FLAG_NOFS); 238 if (!page) 239 return ERR_PTR(-ENOMEM); 240 241 set_new_dnode(&dn, inode, NULL, NULL, 0); 242 err = get_dnode_of_data(&dn, index, LOOKUP_NODE); 243 if (err) { 244 f2fs_put_page(page, 1); 245 return ERR_PTR(err); 246 } 247 f2fs_put_dnode(&dn); 248 249 if (dn.data_blkaddr == NULL_ADDR) { 250 f2fs_put_page(page, 1); 251 return ERR_PTR(-ENOENT); 252 } 253 254 if (PageUptodate(page)) 255 return page; 256 257 /* 258 * A new dentry page is allocated but not able to be written, since its 259 * new inode page couldn't be allocated due to -ENOSPC. 260 * In such the case, its blkaddr can be remained as NEW_ADDR. 261 * see, f2fs_add_link -> get_new_data_page -> init_inode_metadata. 262 */ 263 if (dn.data_blkaddr == NEW_ADDR) { 264 zero_user_segment(page, 0, PAGE_CACHE_SIZE); 265 SetPageUptodate(page); 266 return page; 267 } 268 269 err = f2fs_readpage(sbi, page, dn.data_blkaddr, READ_SYNC); 270 if (err) 271 return ERR_PTR(err); 272 273 lock_page(page); 274 if (!PageUptodate(page)) { 275 f2fs_put_page(page, 1); 276 return ERR_PTR(-EIO); 277 } 278 if (page->mapping != mapping) { 279 f2fs_put_page(page, 1); 280 goto repeat; 281 } 282 return page; 283 } 284 285 /* 286 * Caller ensures that this data page is never allocated. 287 * A new zero-filled data page is allocated in the page cache. 288 * 289 * Also, caller should grab and release a mutex by calling mutex_lock_op() and 290 * mutex_unlock_op(). 291 * Note that, npage is set only by make_empty_dir. 292 */ 293 struct page *get_new_data_page(struct inode *inode, 294 struct page *npage, pgoff_t index, bool new_i_size) 295 { 296 struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb); 297 struct address_space *mapping = inode->i_mapping; 298 struct page *page; 299 struct dnode_of_data dn; 300 int err; 301 302 set_new_dnode(&dn, inode, npage, npage, 0); 303 err = get_dnode_of_data(&dn, index, ALLOC_NODE); 304 if (err) 305 return ERR_PTR(err); 306 307 if (dn.data_blkaddr == NULL_ADDR) { 308 if (reserve_new_block(&dn)) { 309 if (!npage) 310 f2fs_put_dnode(&dn); 311 return ERR_PTR(-ENOSPC); 312 } 313 } 314 if (!npage) 315 f2fs_put_dnode(&dn); 316 repeat: 317 page = grab_cache_page(mapping, index); 318 if (!page) 319 return ERR_PTR(-ENOMEM); 320 321 if (PageUptodate(page)) 322 return page; 323 324 if (dn.data_blkaddr == NEW_ADDR) { 325 zero_user_segment(page, 0, PAGE_CACHE_SIZE); 326 SetPageUptodate(page); 327 } else { 328 err = f2fs_readpage(sbi, page, dn.data_blkaddr, READ_SYNC); 329 if (err) 330 return ERR_PTR(err); 331 lock_page(page); 332 if (!PageUptodate(page)) { 333 f2fs_put_page(page, 1); 334 return ERR_PTR(-EIO); 335 } 336 if (page->mapping != mapping) { 337 f2fs_put_page(page, 1); 338 goto repeat; 339 } 340 } 341 342 if (new_i_size && 343 i_size_read(inode) < ((index + 1) << PAGE_CACHE_SHIFT)) { 344 i_size_write(inode, ((index + 1) << PAGE_CACHE_SHIFT)); 345 /* Only the directory inode sets new_i_size */ 346 set_inode_flag(F2FS_I(inode), FI_UPDATE_DIR); 347 mark_inode_dirty_sync(inode); 348 } 349 return page; 350 } 351 352 static void read_end_io(struct bio *bio, int err) 353 { 354 const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); 355 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1; 356 357 do { 358 struct page *page = bvec->bv_page; 359 360 if (--bvec >= bio->bi_io_vec) 361 prefetchw(&bvec->bv_page->flags); 362 363 if (uptodate) { 364 SetPageUptodate(page); 365 } else { 366 ClearPageUptodate(page); 367 SetPageError(page); 368 } 369 unlock_page(page); 370 } while (bvec >= bio->bi_io_vec); 371 bio_put(bio); 372 } 373 374 /* 375 * Fill the locked page with data located in the block address. 376 * Return unlocked page. 377 */ 378 int f2fs_readpage(struct f2fs_sb_info *sbi, struct page *page, 379 block_t blk_addr, int type) 380 { 381 struct block_device *bdev = sbi->sb->s_bdev; 382 struct bio *bio; 383 384 trace_f2fs_readpage(page, blk_addr, type); 385 386 down_read(&sbi->bio_sem); 387 388 /* Allocate a new bio */ 389 bio = f2fs_bio_alloc(bdev, 1); 390 391 /* Initialize the bio */ 392 bio->bi_sector = SECTOR_FROM_BLOCK(sbi, blk_addr); 393 bio->bi_end_io = read_end_io; 394 395 if (bio_add_page(bio, page, PAGE_CACHE_SIZE, 0) < PAGE_CACHE_SIZE) { 396 bio_put(bio); 397 up_read(&sbi->bio_sem); 398 f2fs_put_page(page, 1); 399 return -EFAULT; 400 } 401 402 submit_bio(type, bio); 403 up_read(&sbi->bio_sem); 404 return 0; 405 } 406 407 /* 408 * This function should be used by the data read flow only where it 409 * does not check the "create" flag that indicates block allocation. 410 * The reason for this special functionality is to exploit VFS readahead 411 * mechanism. 412 */ 413 static int get_data_block_ro(struct inode *inode, sector_t iblock, 414 struct buffer_head *bh_result, int create) 415 { 416 unsigned int blkbits = inode->i_sb->s_blocksize_bits; 417 unsigned maxblocks = bh_result->b_size >> blkbits; 418 struct dnode_of_data dn; 419 pgoff_t pgofs; 420 int err; 421 422 /* Get the page offset from the block offset(iblock) */ 423 pgofs = (pgoff_t)(iblock >> (PAGE_CACHE_SHIFT - blkbits)); 424 425 if (check_extent_cache(inode, pgofs, bh_result)) { 426 trace_f2fs_get_data_block(inode, iblock, bh_result, 0); 427 return 0; 428 } 429 430 /* When reading holes, we need its node page */ 431 set_new_dnode(&dn, inode, NULL, NULL, 0); 432 err = get_dnode_of_data(&dn, pgofs, LOOKUP_NODE_RA); 433 if (err) { 434 trace_f2fs_get_data_block(inode, iblock, bh_result, err); 435 return (err == -ENOENT) ? 0 : err; 436 } 437 438 /* It does not support data allocation */ 439 f2fs_bug_on(create); 440 441 if (dn.data_blkaddr != NEW_ADDR && dn.data_blkaddr != NULL_ADDR) { 442 int i; 443 unsigned int end_offset; 444 445 end_offset = IS_INODE(dn.node_page) ? 446 ADDRS_PER_INODE(F2FS_I(inode)) : 447 ADDRS_PER_BLOCK; 448 449 clear_buffer_new(bh_result); 450 451 /* Give more consecutive addresses for the read ahead */ 452 for (i = 0; i < end_offset - dn.ofs_in_node; i++) 453 if (((datablock_addr(dn.node_page, 454 dn.ofs_in_node + i)) 455 != (dn.data_blkaddr + i)) || maxblocks == i) 456 break; 457 map_bh(bh_result, inode->i_sb, dn.data_blkaddr); 458 bh_result->b_size = (i << blkbits); 459 } 460 f2fs_put_dnode(&dn); 461 trace_f2fs_get_data_block(inode, iblock, bh_result, 0); 462 return 0; 463 } 464 465 static int f2fs_read_data_page(struct file *file, struct page *page) 466 { 467 return mpage_readpage(page, get_data_block_ro); 468 } 469 470 static int f2fs_read_data_pages(struct file *file, 471 struct address_space *mapping, 472 struct list_head *pages, unsigned nr_pages) 473 { 474 return mpage_readpages(mapping, pages, nr_pages, get_data_block_ro); 475 } 476 477 int do_write_data_page(struct page *page) 478 { 479 struct inode *inode = page->mapping->host; 480 block_t old_blk_addr, new_blk_addr; 481 struct dnode_of_data dn; 482 int err = 0; 483 484 set_new_dnode(&dn, inode, NULL, NULL, 0); 485 err = get_dnode_of_data(&dn, page->index, LOOKUP_NODE); 486 if (err) 487 return err; 488 489 old_blk_addr = dn.data_blkaddr; 490 491 /* This page is already truncated */ 492 if (old_blk_addr == NULL_ADDR) 493 goto out_writepage; 494 495 set_page_writeback(page); 496 497 /* 498 * If current allocation needs SSR, 499 * it had better in-place writes for updated data. 500 */ 501 if (unlikely(old_blk_addr != NEW_ADDR && 502 !is_cold_data(page) && 503 need_inplace_update(inode))) { 504 rewrite_data_page(F2FS_SB(inode->i_sb), page, 505 old_blk_addr); 506 } else { 507 write_data_page(inode, page, &dn, 508 old_blk_addr, &new_blk_addr); 509 update_extent_cache(new_blk_addr, &dn); 510 } 511 out_writepage: 512 f2fs_put_dnode(&dn); 513 return err; 514 } 515 516 static int f2fs_write_data_page(struct page *page, 517 struct writeback_control *wbc) 518 { 519 struct inode *inode = page->mapping->host; 520 struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb); 521 loff_t i_size = i_size_read(inode); 522 const pgoff_t end_index = ((unsigned long long) i_size) 523 >> PAGE_CACHE_SHIFT; 524 unsigned offset; 525 bool need_balance_fs = false; 526 int err = 0; 527 528 if (page->index < end_index) 529 goto write; 530 531 /* 532 * If the offset is out-of-range of file size, 533 * this page does not have to be written to disk. 534 */ 535 offset = i_size & (PAGE_CACHE_SIZE - 1); 536 if ((page->index >= end_index + 1) || !offset) { 537 if (S_ISDIR(inode->i_mode)) { 538 dec_page_count(sbi, F2FS_DIRTY_DENTS); 539 inode_dec_dirty_dents(inode); 540 } 541 goto out; 542 } 543 544 zero_user_segment(page, offset, PAGE_CACHE_SIZE); 545 write: 546 if (sbi->por_doing) { 547 err = AOP_WRITEPAGE_ACTIVATE; 548 goto redirty_out; 549 } 550 551 /* Dentry blocks are controlled by checkpoint */ 552 if (S_ISDIR(inode->i_mode)) { 553 dec_page_count(sbi, F2FS_DIRTY_DENTS); 554 inode_dec_dirty_dents(inode); 555 err = do_write_data_page(page); 556 } else { 557 f2fs_lock_op(sbi); 558 err = do_write_data_page(page); 559 f2fs_unlock_op(sbi); 560 need_balance_fs = true; 561 } 562 if (err == -ENOENT) 563 goto out; 564 else if (err) 565 goto redirty_out; 566 567 if (wbc->for_reclaim) 568 f2fs_submit_bio(sbi, DATA, true); 569 570 clear_cold_data(page); 571 out: 572 unlock_page(page); 573 if (need_balance_fs) 574 f2fs_balance_fs(sbi); 575 return 0; 576 577 redirty_out: 578 wbc->pages_skipped++; 579 set_page_dirty(page); 580 return err; 581 } 582 583 #define MAX_DESIRED_PAGES_WP 4096 584 585 static int __f2fs_writepage(struct page *page, struct writeback_control *wbc, 586 void *data) 587 { 588 struct address_space *mapping = data; 589 int ret = mapping->a_ops->writepage(page, wbc); 590 mapping_set_error(mapping, ret); 591 return ret; 592 } 593 594 static int f2fs_write_data_pages(struct address_space *mapping, 595 struct writeback_control *wbc) 596 { 597 struct inode *inode = mapping->host; 598 struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb); 599 bool locked = false; 600 int ret; 601 long excess_nrtw = 0, desired_nrtw; 602 603 /* deal with chardevs and other special file */ 604 if (!mapping->a_ops->writepage) 605 return 0; 606 607 if (wbc->nr_to_write < MAX_DESIRED_PAGES_WP) { 608 desired_nrtw = MAX_DESIRED_PAGES_WP; 609 excess_nrtw = desired_nrtw - wbc->nr_to_write; 610 wbc->nr_to_write = desired_nrtw; 611 } 612 613 if (!S_ISDIR(inode->i_mode)) { 614 mutex_lock(&sbi->writepages); 615 locked = true; 616 } 617 ret = write_cache_pages(mapping, wbc, __f2fs_writepage, mapping); 618 if (locked) 619 mutex_unlock(&sbi->writepages); 620 f2fs_submit_bio(sbi, DATA, (wbc->sync_mode == WB_SYNC_ALL)); 621 622 remove_dirty_dir_inode(inode); 623 624 wbc->nr_to_write -= excess_nrtw; 625 return ret; 626 } 627 628 static int f2fs_write_begin(struct file *file, struct address_space *mapping, 629 loff_t pos, unsigned len, unsigned flags, 630 struct page **pagep, void **fsdata) 631 { 632 struct inode *inode = mapping->host; 633 struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb); 634 struct page *page; 635 pgoff_t index = ((unsigned long long) pos) >> PAGE_CACHE_SHIFT; 636 struct dnode_of_data dn; 637 int err = 0; 638 639 f2fs_balance_fs(sbi); 640 repeat: 641 page = grab_cache_page_write_begin(mapping, index, flags); 642 if (!page) 643 return -ENOMEM; 644 *pagep = page; 645 646 f2fs_lock_op(sbi); 647 648 set_new_dnode(&dn, inode, NULL, NULL, 0); 649 err = get_dnode_of_data(&dn, index, ALLOC_NODE); 650 if (err) 651 goto err; 652 653 if (dn.data_blkaddr == NULL_ADDR) 654 err = reserve_new_block(&dn); 655 656 f2fs_put_dnode(&dn); 657 if (err) 658 goto err; 659 660 f2fs_unlock_op(sbi); 661 662 if ((len == PAGE_CACHE_SIZE) || PageUptodate(page)) 663 return 0; 664 665 if ((pos & PAGE_CACHE_MASK) >= i_size_read(inode)) { 666 unsigned start = pos & (PAGE_CACHE_SIZE - 1); 667 unsigned end = start + len; 668 669 /* Reading beyond i_size is simple: memset to zero */ 670 zero_user_segments(page, 0, start, end, PAGE_CACHE_SIZE); 671 goto out; 672 } 673 674 if (dn.data_blkaddr == NEW_ADDR) { 675 zero_user_segment(page, 0, PAGE_CACHE_SIZE); 676 } else { 677 err = f2fs_readpage(sbi, page, dn.data_blkaddr, READ_SYNC); 678 if (err) 679 return err; 680 lock_page(page); 681 if (!PageUptodate(page)) { 682 f2fs_put_page(page, 1); 683 return -EIO; 684 } 685 if (page->mapping != mapping) { 686 f2fs_put_page(page, 1); 687 goto repeat; 688 } 689 } 690 out: 691 SetPageUptodate(page); 692 clear_cold_data(page); 693 return 0; 694 695 err: 696 f2fs_unlock_op(sbi); 697 f2fs_put_page(page, 1); 698 return err; 699 } 700 701 static int f2fs_write_end(struct file *file, 702 struct address_space *mapping, 703 loff_t pos, unsigned len, unsigned copied, 704 struct page *page, void *fsdata) 705 { 706 struct inode *inode = page->mapping->host; 707 708 SetPageUptodate(page); 709 set_page_dirty(page); 710 711 if (pos + copied > i_size_read(inode)) { 712 i_size_write(inode, pos + copied); 713 mark_inode_dirty(inode); 714 update_inode_page(inode); 715 } 716 717 unlock_page(page); 718 page_cache_release(page); 719 return copied; 720 } 721 722 static ssize_t f2fs_direct_IO(int rw, struct kiocb *iocb, 723 const struct iovec *iov, loff_t offset, unsigned long nr_segs) 724 { 725 struct file *file = iocb->ki_filp; 726 struct inode *inode = file->f_mapping->host; 727 728 if (rw == WRITE) 729 return 0; 730 731 /* Needs synchronization with the cleaner */ 732 return blockdev_direct_IO(rw, iocb, inode, iov, offset, nr_segs, 733 get_data_block_ro); 734 } 735 736 static void f2fs_invalidate_data_page(struct page *page, unsigned int offset, 737 unsigned int length) 738 { 739 struct inode *inode = page->mapping->host; 740 struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb); 741 if (S_ISDIR(inode->i_mode) && PageDirty(page)) { 742 dec_page_count(sbi, F2FS_DIRTY_DENTS); 743 inode_dec_dirty_dents(inode); 744 } 745 ClearPagePrivate(page); 746 } 747 748 static int f2fs_release_data_page(struct page *page, gfp_t wait) 749 { 750 ClearPagePrivate(page); 751 return 1; 752 } 753 754 static int f2fs_set_data_page_dirty(struct page *page) 755 { 756 struct address_space *mapping = page->mapping; 757 struct inode *inode = mapping->host; 758 759 trace_f2fs_set_page_dirty(page, DATA); 760 761 SetPageUptodate(page); 762 if (!PageDirty(page)) { 763 __set_page_dirty_nobuffers(page); 764 set_dirty_dir_page(inode, page); 765 return 1; 766 } 767 return 0; 768 } 769 770 static sector_t f2fs_bmap(struct address_space *mapping, sector_t block) 771 { 772 return generic_block_bmap(mapping, block, get_data_block_ro); 773 } 774 775 const struct address_space_operations f2fs_dblock_aops = { 776 .readpage = f2fs_read_data_page, 777 .readpages = f2fs_read_data_pages, 778 .writepage = f2fs_write_data_page, 779 .writepages = f2fs_write_data_pages, 780 .write_begin = f2fs_write_begin, 781 .write_end = f2fs_write_end, 782 .set_page_dirty = f2fs_set_data_page_dirty, 783 .invalidatepage = f2fs_invalidate_data_page, 784 .releasepage = f2fs_release_data_page, 785 .direct_IO = f2fs_direct_IO, 786 .bmap = f2fs_bmap, 787 }; 788