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 * Low-level block read/write IO operations. 29 */ 30 static struct bio *__bio_alloc(struct block_device *bdev, int npages) 31 { 32 struct bio *bio; 33 34 /* No failure on bio allocation */ 35 bio = bio_alloc(GFP_NOIO, npages); 36 bio->bi_bdev = bdev; 37 bio->bi_private = NULL; 38 return bio; 39 } 40 41 static void f2fs_read_end_io(struct bio *bio, int err) 42 { 43 const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); 44 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1; 45 46 do { 47 struct page *page = bvec->bv_page; 48 49 if (--bvec >= bio->bi_io_vec) 50 prefetchw(&bvec->bv_page->flags); 51 52 if (uptodate) { 53 SetPageUptodate(page); 54 } else { 55 ClearPageUptodate(page); 56 SetPageError(page); 57 } 58 unlock_page(page); 59 } while (bvec >= bio->bi_io_vec); 60 61 bio_put(bio); 62 } 63 64 static void f2fs_write_end_io(struct bio *bio, int err) 65 { 66 const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); 67 struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1; 68 struct f2fs_sb_info *sbi = F2FS_SB(bvec->bv_page->mapping->host->i_sb); 69 70 do { 71 struct page *page = bvec->bv_page; 72 73 if (--bvec >= bio->bi_io_vec) 74 prefetchw(&bvec->bv_page->flags); 75 76 if (!uptodate) { 77 SetPageError(page); 78 set_bit(AS_EIO, &page->mapping->flags); 79 set_ckpt_flags(sbi->ckpt, CP_ERROR_FLAG); 80 sbi->sb->s_flags |= MS_RDONLY; 81 } 82 end_page_writeback(page); 83 dec_page_count(sbi, F2FS_WRITEBACK); 84 } while (bvec >= bio->bi_io_vec); 85 86 if (bio->bi_private) 87 complete(bio->bi_private); 88 89 if (!get_pages(sbi, F2FS_WRITEBACK) && 90 !list_empty(&sbi->cp_wait.task_list)) 91 wake_up(&sbi->cp_wait); 92 93 bio_put(bio); 94 } 95 96 static void __submit_merged_bio(struct f2fs_sb_info *sbi, 97 struct f2fs_bio_info *io, 98 enum page_type type, bool sync, int rw) 99 { 100 enum page_type btype = PAGE_TYPE_OF_BIO(type); 101 102 if (!io->bio) 103 return; 104 105 if (btype == META) 106 rw |= REQ_META; 107 108 if (is_read_io(rw)) { 109 if (sync) 110 rw |= READ_SYNC; 111 submit_bio(rw, io->bio); 112 trace_f2fs_submit_read_bio(sbi->sb, rw, type, io->bio); 113 io->bio = NULL; 114 return; 115 } 116 117 if (sync) 118 rw |= WRITE_SYNC; 119 if (type >= META_FLUSH) 120 rw |= WRITE_FLUSH_FUA; 121 122 /* 123 * META_FLUSH is only from the checkpoint procedure, and we should wait 124 * this metadata bio for FS consistency. 125 */ 126 if (type == META_FLUSH) { 127 DECLARE_COMPLETION_ONSTACK(wait); 128 io->bio->bi_private = &wait; 129 submit_bio(rw, io->bio); 130 wait_for_completion(&wait); 131 } else { 132 submit_bio(rw, io->bio); 133 } 134 trace_f2fs_submit_write_bio(sbi->sb, rw, btype, io->bio); 135 io->bio = NULL; 136 } 137 138 void f2fs_submit_merged_bio(struct f2fs_sb_info *sbi, 139 enum page_type type, bool sync, int rw) 140 { 141 enum page_type btype = PAGE_TYPE_OF_BIO(type); 142 struct f2fs_bio_info *io; 143 144 io = is_read_io(rw) ? &sbi->read_io : &sbi->write_io[btype]; 145 146 mutex_lock(&io->io_mutex); 147 __submit_merged_bio(sbi, io, type, sync, rw); 148 mutex_unlock(&io->io_mutex); 149 } 150 151 /* 152 * Fill the locked page with data located in the block address. 153 * Return unlocked page. 154 */ 155 int f2fs_submit_page_bio(struct f2fs_sb_info *sbi, struct page *page, 156 block_t blk_addr, int rw) 157 { 158 struct block_device *bdev = sbi->sb->s_bdev; 159 struct bio *bio; 160 161 trace_f2fs_submit_page_bio(page, blk_addr, rw); 162 163 /* Allocate a new bio */ 164 bio = __bio_alloc(bdev, 1); 165 166 /* Initialize the bio */ 167 bio->bi_sector = SECTOR_FROM_BLOCK(sbi, blk_addr); 168 bio->bi_end_io = is_read_io(rw) ? f2fs_read_end_io : f2fs_write_end_io; 169 170 if (bio_add_page(bio, page, PAGE_CACHE_SIZE, 0) < PAGE_CACHE_SIZE) { 171 bio_put(bio); 172 f2fs_put_page(page, 1); 173 return -EFAULT; 174 } 175 176 submit_bio(rw, bio); 177 return 0; 178 } 179 180 void f2fs_submit_page_mbio(struct f2fs_sb_info *sbi, struct page *page, 181 block_t blk_addr, enum page_type type, int rw) 182 { 183 enum page_type btype = PAGE_TYPE_OF_BIO(type); 184 struct block_device *bdev = sbi->sb->s_bdev; 185 struct f2fs_bio_info *io; 186 int bio_blocks; 187 188 io = is_read_io(rw) ? &sbi->read_io : &sbi->write_io[btype]; 189 190 verify_block_addr(sbi, blk_addr); 191 192 mutex_lock(&io->io_mutex); 193 194 if (!is_read_io(rw)) 195 inc_page_count(sbi, F2FS_WRITEBACK); 196 197 if (io->bio && io->last_block_in_bio != blk_addr - 1) 198 __submit_merged_bio(sbi, io, type, true, rw); 199 alloc_new: 200 if (io->bio == NULL) { 201 bio_blocks = MAX_BIO_BLOCKS(max_hw_blocks(sbi)); 202 io->bio = __bio_alloc(bdev, bio_blocks); 203 io->bio->bi_sector = SECTOR_FROM_BLOCK(sbi, blk_addr); 204 io->bio->bi_end_io = is_read_io(rw) ? f2fs_read_end_io : 205 f2fs_write_end_io; 206 /* 207 * The end_io will be assigned at the sumbission phase. 208 * Until then, let bio_add_page() merge consecutive IOs as much 209 * as possible. 210 */ 211 } 212 213 if (bio_add_page(io->bio, page, PAGE_CACHE_SIZE, 0) < 214 PAGE_CACHE_SIZE) { 215 __submit_merged_bio(sbi, io, type, true, rw); 216 goto alloc_new; 217 } 218 219 io->last_block_in_bio = blk_addr; 220 221 mutex_unlock(&io->io_mutex); 222 trace_f2fs_submit_page_mbio(page, rw, type, blk_addr); 223 } 224 225 /* 226 * Lock ordering for the change of data block address: 227 * ->data_page 228 * ->node_page 229 * update block addresses in the node page 230 */ 231 static void __set_data_blkaddr(struct dnode_of_data *dn, block_t new_addr) 232 { 233 struct f2fs_node *rn; 234 __le32 *addr_array; 235 struct page *node_page = dn->node_page; 236 unsigned int ofs_in_node = dn->ofs_in_node; 237 238 f2fs_wait_on_page_writeback(node_page, NODE, false); 239 240 rn = F2FS_NODE(node_page); 241 242 /* Get physical address of data block */ 243 addr_array = blkaddr_in_node(rn); 244 addr_array[ofs_in_node] = cpu_to_le32(new_addr); 245 set_page_dirty(node_page); 246 } 247 248 int reserve_new_block(struct dnode_of_data *dn) 249 { 250 struct f2fs_sb_info *sbi = F2FS_SB(dn->inode->i_sb); 251 252 if (is_inode_flag_set(F2FS_I(dn->inode), FI_NO_ALLOC)) 253 return -EPERM; 254 if (unlikely(!inc_valid_block_count(sbi, dn->inode, 1))) 255 return -ENOSPC; 256 257 trace_f2fs_reserve_new_block(dn->inode, dn->nid, dn->ofs_in_node); 258 259 __set_data_blkaddr(dn, NEW_ADDR); 260 dn->data_blkaddr = NEW_ADDR; 261 sync_inode_page(dn); 262 return 0; 263 } 264 265 int f2fs_reserve_block(struct dnode_of_data *dn, pgoff_t index) 266 { 267 bool need_put = dn->inode_page ? false : true; 268 int err; 269 270 err = get_dnode_of_data(dn, index, ALLOC_NODE); 271 if (err) 272 return err; 273 if (dn->data_blkaddr == NULL_ADDR) 274 err = reserve_new_block(dn); 275 276 if (need_put) 277 f2fs_put_dnode(dn); 278 return err; 279 } 280 281 static int check_extent_cache(struct inode *inode, pgoff_t pgofs, 282 struct buffer_head *bh_result) 283 { 284 struct f2fs_inode_info *fi = F2FS_I(inode); 285 pgoff_t start_fofs, end_fofs; 286 block_t start_blkaddr; 287 288 if (is_inode_flag_set(fi, FI_NO_EXTENT)) 289 return 0; 290 291 read_lock(&fi->ext.ext_lock); 292 if (fi->ext.len == 0) { 293 read_unlock(&fi->ext.ext_lock); 294 return 0; 295 } 296 297 stat_inc_total_hit(inode->i_sb); 298 299 start_fofs = fi->ext.fofs; 300 end_fofs = fi->ext.fofs + fi->ext.len - 1; 301 start_blkaddr = fi->ext.blk_addr; 302 303 if (pgofs >= start_fofs && pgofs <= end_fofs) { 304 unsigned int blkbits = inode->i_sb->s_blocksize_bits; 305 size_t count; 306 307 clear_buffer_new(bh_result); 308 map_bh(bh_result, inode->i_sb, 309 start_blkaddr + pgofs - start_fofs); 310 count = end_fofs - pgofs + 1; 311 if (count < (UINT_MAX >> blkbits)) 312 bh_result->b_size = (count << blkbits); 313 else 314 bh_result->b_size = UINT_MAX; 315 316 stat_inc_read_hit(inode->i_sb); 317 read_unlock(&fi->ext.ext_lock); 318 return 1; 319 } 320 read_unlock(&fi->ext.ext_lock); 321 return 0; 322 } 323 324 void update_extent_cache(block_t blk_addr, struct dnode_of_data *dn) 325 { 326 struct f2fs_inode_info *fi = F2FS_I(dn->inode); 327 pgoff_t fofs, start_fofs, end_fofs; 328 block_t start_blkaddr, end_blkaddr; 329 int need_update = true; 330 331 f2fs_bug_on(blk_addr == NEW_ADDR); 332 fofs = start_bidx_of_node(ofs_of_node(dn->node_page), fi) + 333 dn->ofs_in_node; 334 335 /* Update the page address in the parent node */ 336 __set_data_blkaddr(dn, blk_addr); 337 338 if (is_inode_flag_set(fi, FI_NO_EXTENT)) 339 return; 340 341 write_lock(&fi->ext.ext_lock); 342 343 start_fofs = fi->ext.fofs; 344 end_fofs = fi->ext.fofs + fi->ext.len - 1; 345 start_blkaddr = fi->ext.blk_addr; 346 end_blkaddr = fi->ext.blk_addr + fi->ext.len - 1; 347 348 /* Drop and initialize the matched extent */ 349 if (fi->ext.len == 1 && fofs == start_fofs) 350 fi->ext.len = 0; 351 352 /* Initial extent */ 353 if (fi->ext.len == 0) { 354 if (blk_addr != NULL_ADDR) { 355 fi->ext.fofs = fofs; 356 fi->ext.blk_addr = blk_addr; 357 fi->ext.len = 1; 358 } 359 goto end_update; 360 } 361 362 /* Front merge */ 363 if (fofs == start_fofs - 1 && blk_addr == start_blkaddr - 1) { 364 fi->ext.fofs--; 365 fi->ext.blk_addr--; 366 fi->ext.len++; 367 goto end_update; 368 } 369 370 /* Back merge */ 371 if (fofs == end_fofs + 1 && blk_addr == end_blkaddr + 1) { 372 fi->ext.len++; 373 goto end_update; 374 } 375 376 /* Split the existing extent */ 377 if (fi->ext.len > 1 && 378 fofs >= start_fofs && fofs <= end_fofs) { 379 if ((end_fofs - fofs) < (fi->ext.len >> 1)) { 380 fi->ext.len = fofs - start_fofs; 381 } else { 382 fi->ext.fofs = fofs + 1; 383 fi->ext.blk_addr = start_blkaddr + 384 fofs - start_fofs + 1; 385 fi->ext.len -= fofs - start_fofs + 1; 386 } 387 } else { 388 need_update = false; 389 } 390 391 /* Finally, if the extent is very fragmented, let's drop the cache. */ 392 if (fi->ext.len < F2FS_MIN_EXTENT_LEN) { 393 fi->ext.len = 0; 394 set_inode_flag(fi, FI_NO_EXTENT); 395 need_update = true; 396 } 397 end_update: 398 write_unlock(&fi->ext.ext_lock); 399 if (need_update) 400 sync_inode_page(dn); 401 return; 402 } 403 404 struct page *find_data_page(struct inode *inode, pgoff_t index, bool sync) 405 { 406 struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb); 407 struct address_space *mapping = inode->i_mapping; 408 struct dnode_of_data dn; 409 struct page *page; 410 int err; 411 412 page = find_get_page(mapping, index); 413 if (page && PageUptodate(page)) 414 return page; 415 f2fs_put_page(page, 0); 416 417 set_new_dnode(&dn, inode, NULL, NULL, 0); 418 err = get_dnode_of_data(&dn, index, LOOKUP_NODE); 419 if (err) 420 return ERR_PTR(err); 421 f2fs_put_dnode(&dn); 422 423 if (dn.data_blkaddr == NULL_ADDR) 424 return ERR_PTR(-ENOENT); 425 426 /* By fallocate(), there is no cached page, but with NEW_ADDR */ 427 if (dn.data_blkaddr == NEW_ADDR) 428 return ERR_PTR(-EINVAL); 429 430 page = grab_cache_page_write_begin(mapping, index, AOP_FLAG_NOFS); 431 if (!page) 432 return ERR_PTR(-ENOMEM); 433 434 if (PageUptodate(page)) { 435 unlock_page(page); 436 return page; 437 } 438 439 err = f2fs_submit_page_bio(sbi, page, dn.data_blkaddr, 440 sync ? READ_SYNC : READA); 441 if (err) 442 return ERR_PTR(err); 443 444 if (sync) { 445 wait_on_page_locked(page); 446 if (!PageUptodate(page)) { 447 f2fs_put_page(page, 0); 448 return ERR_PTR(-EIO); 449 } 450 } 451 return page; 452 } 453 454 /* 455 * If it tries to access a hole, return an error. 456 * Because, the callers, functions in dir.c and GC, should be able to know 457 * whether this page exists or not. 458 */ 459 struct page *get_lock_data_page(struct inode *inode, pgoff_t index) 460 { 461 struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb); 462 struct address_space *mapping = inode->i_mapping; 463 struct dnode_of_data dn; 464 struct page *page; 465 int err; 466 467 repeat: 468 page = grab_cache_page_write_begin(mapping, index, AOP_FLAG_NOFS); 469 if (!page) 470 return ERR_PTR(-ENOMEM); 471 472 set_new_dnode(&dn, inode, NULL, NULL, 0); 473 err = get_dnode_of_data(&dn, index, LOOKUP_NODE); 474 if (err) { 475 f2fs_put_page(page, 1); 476 return ERR_PTR(err); 477 } 478 f2fs_put_dnode(&dn); 479 480 if (dn.data_blkaddr == NULL_ADDR) { 481 f2fs_put_page(page, 1); 482 return ERR_PTR(-ENOENT); 483 } 484 485 if (PageUptodate(page)) 486 return page; 487 488 /* 489 * A new dentry page is allocated but not able to be written, since its 490 * new inode page couldn't be allocated due to -ENOSPC. 491 * In such the case, its blkaddr can be remained as NEW_ADDR. 492 * see, f2fs_add_link -> get_new_data_page -> init_inode_metadata. 493 */ 494 if (dn.data_blkaddr == NEW_ADDR) { 495 zero_user_segment(page, 0, PAGE_CACHE_SIZE); 496 SetPageUptodate(page); 497 return page; 498 } 499 500 err = f2fs_submit_page_bio(sbi, page, dn.data_blkaddr, READ_SYNC); 501 if (err) 502 return ERR_PTR(err); 503 504 lock_page(page); 505 if (!PageUptodate(page)) { 506 f2fs_put_page(page, 1); 507 return ERR_PTR(-EIO); 508 } 509 if (page->mapping != mapping) { 510 f2fs_put_page(page, 1); 511 goto repeat; 512 } 513 return page; 514 } 515 516 /* 517 * Caller ensures that this data page is never allocated. 518 * A new zero-filled data page is allocated in the page cache. 519 * 520 * Also, caller should grab and release a mutex by calling mutex_lock_op() and 521 * mutex_unlock_op(). 522 * Note that, npage is set only by make_empty_dir. 523 */ 524 struct page *get_new_data_page(struct inode *inode, 525 struct page *npage, pgoff_t index, bool new_i_size) 526 { 527 struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb); 528 struct address_space *mapping = inode->i_mapping; 529 struct page *page; 530 struct dnode_of_data dn; 531 int err; 532 533 set_new_dnode(&dn, inode, npage, npage, 0); 534 err = f2fs_reserve_block(&dn, index); 535 if (err) 536 return ERR_PTR(err); 537 538 repeat: 539 page = grab_cache_page(mapping, index); 540 if (!page) 541 return ERR_PTR(-ENOMEM); 542 543 if (PageUptodate(page)) 544 return page; 545 546 if (dn.data_blkaddr == NEW_ADDR) { 547 zero_user_segment(page, 0, PAGE_CACHE_SIZE); 548 SetPageUptodate(page); 549 } else { 550 err = f2fs_submit_page_bio(sbi, page, dn.data_blkaddr, 551 READ_SYNC); 552 if (err) 553 return ERR_PTR(err); 554 lock_page(page); 555 if (!PageUptodate(page)) { 556 f2fs_put_page(page, 1); 557 return ERR_PTR(-EIO); 558 } 559 if (page->mapping != mapping) { 560 f2fs_put_page(page, 1); 561 goto repeat; 562 } 563 } 564 565 if (new_i_size && 566 i_size_read(inode) < ((index + 1) << PAGE_CACHE_SHIFT)) { 567 i_size_write(inode, ((index + 1) << PAGE_CACHE_SHIFT)); 568 /* Only the directory inode sets new_i_size */ 569 set_inode_flag(F2FS_I(inode), FI_UPDATE_DIR); 570 mark_inode_dirty_sync(inode); 571 } 572 return page; 573 } 574 575 /* 576 * This function should be used by the data read flow only where it 577 * does not check the "create" flag that indicates block allocation. 578 * The reason for this special functionality is to exploit VFS readahead 579 * mechanism. 580 */ 581 static int get_data_block_ro(struct inode *inode, sector_t iblock, 582 struct buffer_head *bh_result, int create) 583 { 584 unsigned int blkbits = inode->i_sb->s_blocksize_bits; 585 unsigned maxblocks = bh_result->b_size >> blkbits; 586 struct dnode_of_data dn; 587 pgoff_t pgofs; 588 int err; 589 590 /* Get the page offset from the block offset(iblock) */ 591 pgofs = (pgoff_t)(iblock >> (PAGE_CACHE_SHIFT - blkbits)); 592 593 if (check_extent_cache(inode, pgofs, bh_result)) { 594 trace_f2fs_get_data_block(inode, iblock, bh_result, 0); 595 return 0; 596 } 597 598 /* When reading holes, we need its node page */ 599 set_new_dnode(&dn, inode, NULL, NULL, 0); 600 err = get_dnode_of_data(&dn, pgofs, LOOKUP_NODE_RA); 601 if (err) { 602 trace_f2fs_get_data_block(inode, iblock, bh_result, err); 603 return (err == -ENOENT) ? 0 : err; 604 } 605 606 /* It does not support data allocation */ 607 f2fs_bug_on(create); 608 609 if (dn.data_blkaddr != NEW_ADDR && dn.data_blkaddr != NULL_ADDR) { 610 int i; 611 unsigned int end_offset; 612 613 end_offset = IS_INODE(dn.node_page) ? 614 ADDRS_PER_INODE(F2FS_I(inode)) : 615 ADDRS_PER_BLOCK; 616 617 clear_buffer_new(bh_result); 618 619 /* Give more consecutive addresses for the read ahead */ 620 for (i = 0; i < end_offset - dn.ofs_in_node; i++) 621 if (((datablock_addr(dn.node_page, 622 dn.ofs_in_node + i)) 623 != (dn.data_blkaddr + i)) || maxblocks == i) 624 break; 625 map_bh(bh_result, inode->i_sb, dn.data_blkaddr); 626 bh_result->b_size = (((size_t)i) << blkbits); 627 } 628 f2fs_put_dnode(&dn); 629 trace_f2fs_get_data_block(inode, iblock, bh_result, 0); 630 return 0; 631 } 632 633 static int f2fs_read_data_page(struct file *file, struct page *page) 634 { 635 return mpage_readpage(page, get_data_block_ro); 636 } 637 638 static int f2fs_read_data_pages(struct file *file, 639 struct address_space *mapping, 640 struct list_head *pages, unsigned nr_pages) 641 { 642 return mpage_readpages(mapping, pages, nr_pages, get_data_block_ro); 643 } 644 645 int do_write_data_page(struct page *page) 646 { 647 struct inode *inode = page->mapping->host; 648 block_t old_blk_addr, new_blk_addr; 649 struct dnode_of_data dn; 650 int err = 0; 651 652 set_new_dnode(&dn, inode, NULL, NULL, 0); 653 err = get_dnode_of_data(&dn, page->index, LOOKUP_NODE); 654 if (err) 655 return err; 656 657 old_blk_addr = dn.data_blkaddr; 658 659 /* This page is already truncated */ 660 if (old_blk_addr == NULL_ADDR) 661 goto out_writepage; 662 663 set_page_writeback(page); 664 665 /* 666 * If current allocation needs SSR, 667 * it had better in-place writes for updated data. 668 */ 669 if (unlikely(old_blk_addr != NEW_ADDR && 670 !is_cold_data(page) && 671 need_inplace_update(inode))) { 672 rewrite_data_page(F2FS_SB(inode->i_sb), page, 673 old_blk_addr); 674 } else { 675 write_data_page(inode, page, &dn, 676 old_blk_addr, &new_blk_addr); 677 update_extent_cache(new_blk_addr, &dn); 678 } 679 out_writepage: 680 f2fs_put_dnode(&dn); 681 return err; 682 } 683 684 static int f2fs_write_data_page(struct page *page, 685 struct writeback_control *wbc) 686 { 687 struct inode *inode = page->mapping->host; 688 struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb); 689 loff_t i_size = i_size_read(inode); 690 const pgoff_t end_index = ((unsigned long long) i_size) 691 >> PAGE_CACHE_SHIFT; 692 unsigned offset; 693 bool need_balance_fs = false; 694 int err = 0; 695 696 if (page->index < end_index) 697 goto write; 698 699 /* 700 * If the offset is out-of-range of file size, 701 * this page does not have to be written to disk. 702 */ 703 offset = i_size & (PAGE_CACHE_SIZE - 1); 704 if ((page->index >= end_index + 1) || !offset) { 705 if (S_ISDIR(inode->i_mode)) { 706 dec_page_count(sbi, F2FS_DIRTY_DENTS); 707 inode_dec_dirty_dents(inode); 708 } 709 goto out; 710 } 711 712 zero_user_segment(page, offset, PAGE_CACHE_SIZE); 713 write: 714 if (unlikely(sbi->por_doing)) { 715 err = AOP_WRITEPAGE_ACTIVATE; 716 goto redirty_out; 717 } 718 719 /* Dentry blocks are controlled by checkpoint */ 720 if (S_ISDIR(inode->i_mode)) { 721 dec_page_count(sbi, F2FS_DIRTY_DENTS); 722 inode_dec_dirty_dents(inode); 723 err = do_write_data_page(page); 724 } else { 725 f2fs_lock_op(sbi); 726 err = do_write_data_page(page); 727 f2fs_unlock_op(sbi); 728 need_balance_fs = true; 729 } 730 if (err == -ENOENT) 731 goto out; 732 else if (err) 733 goto redirty_out; 734 735 if (wbc->for_reclaim) 736 f2fs_submit_merged_bio(sbi, DATA, true, WRITE); 737 738 clear_cold_data(page); 739 out: 740 unlock_page(page); 741 if (need_balance_fs) 742 f2fs_balance_fs(sbi); 743 return 0; 744 745 redirty_out: 746 wbc->pages_skipped++; 747 set_page_dirty(page); 748 return err; 749 } 750 751 #define MAX_DESIRED_PAGES_WP 4096 752 753 static int __f2fs_writepage(struct page *page, struct writeback_control *wbc, 754 void *data) 755 { 756 struct address_space *mapping = data; 757 int ret = mapping->a_ops->writepage(page, wbc); 758 mapping_set_error(mapping, ret); 759 return ret; 760 } 761 762 static int f2fs_write_data_pages(struct address_space *mapping, 763 struct writeback_control *wbc) 764 { 765 struct inode *inode = mapping->host; 766 struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb); 767 bool locked = false; 768 int ret; 769 long excess_nrtw = 0, desired_nrtw; 770 771 /* deal with chardevs and other special file */ 772 if (!mapping->a_ops->writepage) 773 return 0; 774 775 if (wbc->nr_to_write < MAX_DESIRED_PAGES_WP) { 776 desired_nrtw = MAX_DESIRED_PAGES_WP; 777 excess_nrtw = desired_nrtw - wbc->nr_to_write; 778 wbc->nr_to_write = desired_nrtw; 779 } 780 781 if (!S_ISDIR(inode->i_mode)) { 782 mutex_lock(&sbi->writepages); 783 locked = true; 784 } 785 ret = write_cache_pages(mapping, wbc, __f2fs_writepage, mapping); 786 if (locked) 787 mutex_unlock(&sbi->writepages); 788 f2fs_submit_merged_bio(sbi, DATA, wbc->sync_mode == WB_SYNC_ALL, WRITE); 789 790 remove_dirty_dir_inode(inode); 791 792 wbc->nr_to_write -= excess_nrtw; 793 return ret; 794 } 795 796 static int f2fs_write_begin(struct file *file, struct address_space *mapping, 797 loff_t pos, unsigned len, unsigned flags, 798 struct page **pagep, void **fsdata) 799 { 800 struct inode *inode = mapping->host; 801 struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb); 802 struct page *page; 803 pgoff_t index = ((unsigned long long) pos) >> PAGE_CACHE_SHIFT; 804 struct dnode_of_data dn; 805 int err = 0; 806 807 f2fs_balance_fs(sbi); 808 repeat: 809 page = grab_cache_page_write_begin(mapping, index, flags); 810 if (!page) 811 return -ENOMEM; 812 *pagep = page; 813 814 f2fs_lock_op(sbi); 815 set_new_dnode(&dn, inode, NULL, NULL, 0); 816 err = f2fs_reserve_block(&dn, index); 817 f2fs_unlock_op(sbi); 818 819 if (err) { 820 f2fs_put_page(page, 1); 821 return err; 822 } 823 824 if ((len == PAGE_CACHE_SIZE) || PageUptodate(page)) 825 return 0; 826 827 if ((pos & PAGE_CACHE_MASK) >= i_size_read(inode)) { 828 unsigned start = pos & (PAGE_CACHE_SIZE - 1); 829 unsigned end = start + len; 830 831 /* Reading beyond i_size is simple: memset to zero */ 832 zero_user_segments(page, 0, start, end, PAGE_CACHE_SIZE); 833 goto out; 834 } 835 836 if (dn.data_blkaddr == NEW_ADDR) { 837 zero_user_segment(page, 0, PAGE_CACHE_SIZE); 838 } else { 839 err = f2fs_submit_page_bio(sbi, page, dn.data_blkaddr, 840 READ_SYNC); 841 if (err) 842 return err; 843 lock_page(page); 844 if (!PageUptodate(page)) { 845 f2fs_put_page(page, 1); 846 return -EIO; 847 } 848 if (page->mapping != mapping) { 849 f2fs_put_page(page, 1); 850 goto repeat; 851 } 852 } 853 out: 854 SetPageUptodate(page); 855 clear_cold_data(page); 856 return 0; 857 } 858 859 static int f2fs_write_end(struct file *file, 860 struct address_space *mapping, 861 loff_t pos, unsigned len, unsigned copied, 862 struct page *page, void *fsdata) 863 { 864 struct inode *inode = page->mapping->host; 865 866 SetPageUptodate(page); 867 set_page_dirty(page); 868 869 if (pos + copied > i_size_read(inode)) { 870 i_size_write(inode, pos + copied); 871 mark_inode_dirty(inode); 872 update_inode_page(inode); 873 } 874 875 f2fs_put_page(page, 1); 876 return copied; 877 } 878 879 static ssize_t f2fs_direct_IO(int rw, struct kiocb *iocb, 880 const struct iovec *iov, loff_t offset, unsigned long nr_segs) 881 { 882 struct file *file = iocb->ki_filp; 883 struct inode *inode = file->f_mapping->host; 884 885 if (rw == WRITE) 886 return 0; 887 888 /* Needs synchronization with the cleaner */ 889 return blockdev_direct_IO(rw, iocb, inode, iov, offset, nr_segs, 890 get_data_block_ro); 891 } 892 893 static void f2fs_invalidate_data_page(struct page *page, unsigned int offset, 894 unsigned int length) 895 { 896 struct inode *inode = page->mapping->host; 897 struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb); 898 if (S_ISDIR(inode->i_mode) && PageDirty(page)) { 899 dec_page_count(sbi, F2FS_DIRTY_DENTS); 900 inode_dec_dirty_dents(inode); 901 } 902 ClearPagePrivate(page); 903 } 904 905 static int f2fs_release_data_page(struct page *page, gfp_t wait) 906 { 907 ClearPagePrivate(page); 908 return 1; 909 } 910 911 static int f2fs_set_data_page_dirty(struct page *page) 912 { 913 struct address_space *mapping = page->mapping; 914 struct inode *inode = mapping->host; 915 916 trace_f2fs_set_page_dirty(page, DATA); 917 918 SetPageUptodate(page); 919 if (!PageDirty(page)) { 920 __set_page_dirty_nobuffers(page); 921 set_dirty_dir_page(inode, page); 922 return 1; 923 } 924 return 0; 925 } 926 927 static sector_t f2fs_bmap(struct address_space *mapping, sector_t block) 928 { 929 return generic_block_bmap(mapping, block, get_data_block_ro); 930 } 931 932 const struct address_space_operations f2fs_dblock_aops = { 933 .readpage = f2fs_read_data_page, 934 .readpages = f2fs_read_data_pages, 935 .writepage = f2fs_write_data_page, 936 .writepages = f2fs_write_data_pages, 937 .write_begin = f2fs_write_begin, 938 .write_end = f2fs_write_end, 939 .set_page_dirty = f2fs_set_data_page_dirty, 940 .invalidatepage = f2fs_invalidate_data_page, 941 .releasepage = f2fs_release_data_page, 942 .direct_IO = f2fs_direct_IO, 943 .bmap = f2fs_bmap, 944 }; 945