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/pagevec.h>
  18 #include <linux/blkdev.h>
  19 #include <linux/bio.h>
  20 #include <linux/prefetch.h>
  21 #include <linux/uio.h>
  22 #include <linux/cleancache.h>
  23
  24 #include "f2fs.h"
  25 #include "node.h"
  26 #include "segment.h"
  27 #include "trace.h"
  28 #include <trace/events/f2fs.h>
  29
  30 static void f2fs_read_end_io(struct bio *bio)
  31 {
  32         struct bio_vec *bvec;
  33         int i;
  34
  35         if (f2fs_bio_encrypted(bio)) {
  36                 if (bio->bi_error) {
  37                         f2fs_release_crypto_ctx(bio->bi_private);
  38                 } else {
  39                         f2fs_end_io_crypto_work(bio->bi_private, bio);
  40                         return;
  41                 }
  42         }
  43
  44         bio_for_each_segment_all(bvec, bio, i) {
  45                 struct page *page = bvec->bv_page;
  46
  47                 if (!bio->bi_error) {
  48                         SetPageUptodate(page);
  49                 } else {
  50                         ClearPageUptodate(page);
  51                         SetPageError(page);
  52                 }
  53                 unlock_page(page);
  54         }
  55         bio_put(bio);
  56 }
  57
  58 static void f2fs_write_end_io(struct bio *bio)
  59 {
  60         struct f2fs_sb_info *sbi = bio->bi_private;
  61         struct bio_vec *bvec;
  62         int i;
  63
  64         bio_for_each_segment_all(bvec, bio, i) {
  65                 struct page *page = bvec->bv_page;
  66
  67                 f2fs_restore_and_release_control_page(&page);
  68
  69                 if (unlikely(bio->bi_error)) {
  70                         set_page_dirty(page);
  71                         set_bit(AS_EIO, &page->mapping->flags);
  72                         f2fs_stop_checkpoint(sbi);
  73                 }
  74                 end_page_writeback(page);
  75                 dec_page_count(sbi, F2FS_WRITEBACK);
  76         }
  77
  78         if (!get_pages(sbi, F2FS_WRITEBACK) &&
  79                         !list_empty(&sbi->cp_wait.task_list))
  80                 wake_up(&sbi->cp_wait);
  81
  82         bio_put(bio);
  83 }
  84
  85 /*
  86  * Low-level block read/write IO operations.
  87  */
  88 static struct bio *__bio_alloc(struct f2fs_sb_info *sbi, block_t blk_addr,
  89                                 int npages, bool is_read)
  90 {
  91         struct bio *bio;
  92
  93         bio = f2fs_bio_alloc(npages);
  94
  95         bio->bi_bdev = sbi->sb->s_bdev;
  96         bio->bi_iter.bi_sector = SECTOR_FROM_BLOCK(blk_addr);
  97         bio->bi_end_io = is_read ? f2fs_read_end_io : f2fs_write_end_io;
  98         bio->bi_private = is_read ? NULL : sbi;
  99
 100         return bio;
 101 }
 102
 103 static void __submit_merged_bio(struct f2fs_bio_info *io)
 104 {
 105         struct f2fs_io_info *fio = &io->fio;
 106
 107         if (!io->bio)
 108                 return;
 109
 110         if (is_read_io(fio->rw))
 111                 trace_f2fs_submit_read_bio(io->sbi->sb, fio, io->bio);
 112         else
 113                 trace_f2fs_submit_write_bio(io->sbi->sb, fio, io->bio);
 114
 115         submit_bio(fio->rw, io->bio);
 116         io->bio = NULL;
 117 }
 118
 119 void f2fs_submit_merged_bio(struct f2fs_sb_info *sbi,
 120                                 enum page_type type, int rw)
 121 {
 122         enum page_type btype = PAGE_TYPE_OF_BIO(type);
 123         struct f2fs_bio_info *io;
 124
 125         io = is_read_io(rw) ? &sbi->read_io : &sbi->write_io[btype];
 126
 127         down_write(&io->io_rwsem);
 128
 129         /* change META to META_FLUSH in the checkpoint procedure */
 130         if (type >= META_FLUSH) {
 131                 io->fio.type = META_FLUSH;
 132                 if (test_opt(sbi, NOBARRIER))
 133                         io->fio.rw = WRITE_FLUSH | REQ_META | REQ_PRIO;
 134                 else
 135                         io->fio.rw = WRITE_FLUSH_FUA | REQ_META | REQ_PRIO;
 136         }
 137         __submit_merged_bio(io);
 138         up_write(&io->io_rwsem);
 139 }
 140
 141 /*
 142  * Fill the locked page with data located in the block address.
 143  * Return unlocked page.
 144  */
 145 int f2fs_submit_page_bio(struct f2fs_io_info *fio)
 146 {
 147         struct bio *bio;
 148         struct page *page = fio->encrypted_page ? fio->encrypted_page : fio->page;
 149
 150         trace_f2fs_submit_page_bio(page, fio);
 151         f2fs_trace_ios(fio, 0);
 152
 153         /* Allocate a new bio */
 154         bio = __bio_alloc(fio->sbi, fio->blk_addr, 1, is_read_io(fio->rw));
 155
 156         if (bio_add_page(bio, page, PAGE_CACHE_SIZE, 0) < PAGE_CACHE_SIZE) {
 157                 bio_put(bio);
 158                 return -EFAULT;
 159         }
 160
 161         submit_bio(fio->rw, bio);
 162         return 0;
 163 }
 164
 165 void f2fs_submit_page_mbio(struct f2fs_io_info *fio)
 166 {
 167         struct f2fs_sb_info *sbi = fio->sbi;
 168         enum page_type btype = PAGE_TYPE_OF_BIO(fio->type);
 169         struct f2fs_bio_info *io;
 170         bool is_read = is_read_io(fio->rw);
 171         struct page *bio_page;
 172
 173         io = is_read ? &sbi->read_io : &sbi->write_io[btype];
 174
 175         verify_block_addr(sbi, fio->blk_addr);
 176
 177         down_write(&io->io_rwsem);
 178
 179         if (!is_read)
 180                 inc_page_count(sbi, F2FS_WRITEBACK);
 181
 182         if (io->bio && (io->last_block_in_bio != fio->blk_addr - 1 ||
 183                                                 io->fio.rw != fio->rw))
 184                 __submit_merged_bio(io);
 185 alloc_new:
 186         if (io->bio == NULL) {
 187                 int bio_blocks = MAX_BIO_BLOCKS(sbi);
 188
 189                 io->bio = __bio_alloc(sbi, fio->blk_addr, bio_blocks, is_read);
 190                 io->fio = *fio;
 191         }
 192
 193         bio_page = fio->encrypted_page ? fio->encrypted_page : fio->page;
 194
 195         if (bio_add_page(io->bio, bio_page, PAGE_CACHE_SIZE, 0) <
 196                                                         PAGE_CACHE_SIZE) {
 197                 __submit_merged_bio(io);
 198                 goto alloc_new;
 199         }
 200
 201         io->last_block_in_bio = fio->blk_addr;
 202         f2fs_trace_ios(fio, 0);
 203
 204         up_write(&io->io_rwsem);
 205         trace_f2fs_submit_page_mbio(fio->page, fio);
 206 }
 207
 208 /*
 209  * Lock ordering for the change of data block address:
 210  * ->data_page
 211  *  ->node_page
 212  *    update block addresses in the node page
 213  */
 214 void set_data_blkaddr(struct dnode_of_data *dn)
 215 {
 216         struct f2fs_node *rn;
 217         __le32 *addr_array;
 218         struct page *node_page = dn->node_page;
 219         unsigned int ofs_in_node = dn->ofs_in_node;
 220
 221         f2fs_wait_on_page_writeback(node_page, NODE);
 222
 223         rn = F2FS_NODE(node_page);
 224
 225         /* Get physical address of data block */
 226         addr_array = blkaddr_in_node(rn);
 227         addr_array[ofs_in_node] = cpu_to_le32(dn->data_blkaddr);
 228         if (set_page_dirty(node_page))
 229                 dn->node_changed = true;
 230 }
 231
 232 int reserve_new_block(struct dnode_of_data *dn)
 233 {
 234         struct f2fs_sb_info *sbi = F2FS_I_SB(dn->inode);
 235
 236         if (unlikely(is_inode_flag_set(F2FS_I(dn->inode), FI_NO_ALLOC)))
 237                 return -EPERM;
 238         if (unlikely(!inc_valid_block_count(sbi, dn->inode, 1)))
 239                 return -ENOSPC;
 240
 241         trace_f2fs_reserve_new_block(dn->inode, dn->nid, dn->ofs_in_node);
 242
 243         dn->data_blkaddr = NEW_ADDR;
 244         set_data_blkaddr(dn);
 245         mark_inode_dirty(dn->inode);
 246         sync_inode_page(dn);
 247         return 0;
 248 }
 249
 250 int f2fs_reserve_block(struct dnode_of_data *dn, pgoff_t index)
 251 {
 252         bool need_put = dn->inode_page ? false : true;
 253         int err;
 254
 255         err = get_dnode_of_data(dn, index, ALLOC_NODE);
 256         if (err)
 257                 return err;
 258
 259         if (dn->data_blkaddr == NULL_ADDR)
 260                 err = reserve_new_block(dn);
 261         if (err || need_put)
 262                 f2fs_put_dnode(dn);
 263         return err;
 264 }
 265
 266 int f2fs_get_block(struct dnode_of_data *dn, pgoff_t index)
 267 {
 268         struct extent_info ei;
 269         struct inode *inode = dn->inode;
 270
 271         if (f2fs_lookup_extent_cache(inode, index, &ei)) {
 272                 dn->data_blkaddr = ei.blk + index - ei.fofs;
 273                 return 0;
 274         }
 275
 276         return f2fs_reserve_block(dn, index);
 277 }
 278
 279 struct page *get_read_data_page(struct inode *inode, pgoff_t index,
 280                                                 int rw, bool for_write)
 281 {
 282         struct address_space *mapping = inode->i_mapping;
 283         struct dnode_of_data dn;
 284         struct page *page;
 285         struct extent_info ei;
 286         int err;
 287         struct f2fs_io_info fio = {
 288                 .sbi = F2FS_I_SB(inode),
 289                 .type = DATA,
 290                 .rw = rw,
 291                 .encrypted_page = NULL,
 292         };
 293
 294         if (f2fs_encrypted_inode(inode) && S_ISREG(inode->i_mode))
 295                 return read_mapping_page(mapping, index, NULL);
 296
 297         page = f2fs_grab_cache_page(mapping, index, for_write);
 298         if (!page)
 299                 return ERR_PTR(-ENOMEM);
 300
 301         if (f2fs_lookup_extent_cache(inode, index, &ei)) {
 302                 dn.data_blkaddr = ei.blk + index - ei.fofs;
 303                 goto got_it;
 304         }
 305
 306         set_new_dnode(&dn, inode, NULL, NULL, 0);
 307         err = get_dnode_of_data(&dn, index, LOOKUP_NODE);
 308         if (err)
 309                 goto put_err;
 310         f2fs_put_dnode(&dn);
 311
 312         if (unlikely(dn.data_blkaddr == NULL_ADDR)) {
 313                 err = -ENOENT;
 314                 goto put_err;
 315         }
 316 got_it:
 317         if (PageUptodate(page)) {
 318                 unlock_page(page);
 319                 return page;
 320         }
 321
 322         /*
 323          * A new dentry page is allocated but not able to be written, since its
 324          * new inode page couldn't be allocated due to -ENOSPC.
 325          * In such the case, its blkaddr can be remained as NEW_ADDR.
 326          * see, f2fs_add_link -> get_new_data_page -> init_inode_metadata.
 327          */
 328         if (dn.data_blkaddr == NEW_ADDR) {
 329                 zero_user_segment(page, 0, PAGE_CACHE_SIZE);
 330                 SetPageUptodate(page);
 331                 unlock_page(page);
 332                 return page;
 333         }
 334
 335         fio.blk_addr = dn.data_blkaddr;
 336         fio.page = page;
 337         err = f2fs_submit_page_bio(&fio);
 338         if (err)
 339                 goto put_err;
 340         return page;
 341
 342 put_err:
 343         f2fs_put_page(page, 1);
 344         return ERR_PTR(err);
 345 }
 346
 347 struct page *find_data_page(struct inode *inode, pgoff_t index)
 348 {
 349         struct address_space *mapping = inode->i_mapping;
 350         struct page *page;
 351
 352         page = find_get_page(mapping, index);
 353         if (page && PageUptodate(page))
 354                 return page;
 355         f2fs_put_page(page, 0);
 356
 357         page = get_read_data_page(inode, index, READ_SYNC, false);
 358         if (IS_ERR(page))
 359                 return page;
 360
 361         if (PageUptodate(page))
 362                 return page;
 363
 364         wait_on_page_locked(page);
 365         if (unlikely(!PageUptodate(page))) {
 366                 f2fs_put_page(page, 0);
 367                 return ERR_PTR(-EIO);
 368         }
 369         return page;
 370 }
 371
 372 /*
 373  * If it tries to access a hole, return an error.
 374  * Because, the callers, functions in dir.c and GC, should be able to know
 375  * whether this page exists or not.
 376  */
 377 struct page *get_lock_data_page(struct inode *inode, pgoff_t index,
 378                                                         bool for_write)
 379 {
 380         struct address_space *mapping = inode->i_mapping;
 381         struct page *page;
 382 repeat:
 383         page = get_read_data_page(inode, index, READ_SYNC, for_write);
 384         if (IS_ERR(page))
 385                 return page;
 386
 387         /* wait for read completion */
 388         lock_page(page);
 389         if (unlikely(!PageUptodate(page))) {
 390                 f2fs_put_page(page, 1);
 391                 return ERR_PTR(-EIO);
 392         }
 393         if (unlikely(page->mapping != mapping)) {
 394                 f2fs_put_page(page, 1);
 395                 goto repeat;
 396         }
 397         return page;
 398 }
 399
 400 /*
 401  * Caller ensures that this data page is never allocated.
 402  * A new zero-filled data page is allocated in the page cache.
 403  *
 404  * Also, caller should grab and release a rwsem by calling f2fs_lock_op() and
 405  * f2fs_unlock_op().
 406  * Note that, ipage is set only by make_empty_dir, and if any error occur,
 407  * ipage should be released by this function.
 408  */
 409 struct page *get_new_data_page(struct inode *inode,
 410                 struct page *ipage, pgoff_t index, bool new_i_size)
 411 {
 412         struct address_space *mapping = inode->i_mapping;
 413         struct page *page;
 414         struct dnode_of_data dn;
 415         int err;
 416
 417         page = f2fs_grab_cache_page(mapping, index, true);
 418         if (!page) {
 419                 /*
 420                  * before exiting, we should make sure ipage will be released
 421                  * if any error occur.
 422                  */
 423                 f2fs_put_page(ipage, 1);
 424                 return ERR_PTR(-ENOMEM);
 425         }
 426
 427         set_new_dnode(&dn, inode, ipage, NULL, 0);
 428         err = f2fs_reserve_block(&dn, index);
 429         if (err) {
 430                 f2fs_put_page(page, 1);
 431                 return ERR_PTR(err);
 432         }
 433         if (!ipage)
 434                 f2fs_put_dnode(&dn);
 435
 436         if (PageUptodate(page))
 437                 goto got_it;
 438
 439         if (dn.data_blkaddr == NEW_ADDR) {
 440                 zero_user_segment(page, 0, PAGE_CACHE_SIZE);
 441                 SetPageUptodate(page);
 442         } else {
 443                 f2fs_put_page(page, 1);
 444
 445                 /* if ipage exists, blkaddr should be NEW_ADDR */
 446                 f2fs_bug_on(F2FS_I_SB(inode), ipage);
 447                 page = get_lock_data_page(inode, index, true);
 448                 if (IS_ERR(page))
 449                         return page;
 450         }
 451 got_it:
 452         if (new_i_size && i_size_read(inode) <
 453                                 ((loff_t)(index + 1) << PAGE_CACHE_SHIFT)) {
 454                 i_size_write(inode, ((loff_t)(index + 1) << PAGE_CACHE_SHIFT));
 455                 /* Only the directory inode sets new_i_size */
 456                 set_inode_flag(F2FS_I(inode), FI_UPDATE_DIR);
 457         }
 458         return page;
 459 }
 460
 461 static int __allocate_data_block(struct dnode_of_data *dn)
 462 {
 463         struct f2fs_sb_info *sbi = F2FS_I_SB(dn->inode);
 464         struct f2fs_inode_info *fi = F2FS_I(dn->inode);
 465         struct f2fs_summary sum;
 466         struct node_info ni;
 467         int seg = CURSEG_WARM_DATA;
 468         pgoff_t fofs;
 469
 470         if (unlikely(is_inode_flag_set(F2FS_I(dn->inode), FI_NO_ALLOC)))
 471                 return -EPERM;
 472
 473         dn->data_blkaddr = datablock_addr(dn->node_page, dn->ofs_in_node);
 474         if (dn->data_blkaddr == NEW_ADDR)
 475                 goto alloc;
 476
 477         if (unlikely(!inc_valid_block_count(sbi, dn->inode, 1)))
 478                 return -ENOSPC;
 479
 480 alloc:
 481         get_node_info(sbi, dn->nid, &ni);
 482         set_summary(&sum, dn->nid, dn->ofs_in_node, ni.version);
 483
 484         if (dn->ofs_in_node == 0 && dn->inode_page == dn->node_page)
 485                 seg = CURSEG_DIRECT_IO;
 486
 487         allocate_data_block(sbi, NULL, dn->data_blkaddr, &dn->data_blkaddr,
 488                                                                 &sum, seg);
 489         set_data_blkaddr(dn);
 490
 491         /* update i_size */
 492         fofs = start_bidx_of_node(ofs_of_node(dn->node_page), fi) +
 493                                                         dn->ofs_in_node;
 494         if (i_size_read(dn->inode) < ((loff_t)(fofs + 1) << PAGE_CACHE_SHIFT))
 495                 i_size_write(dn->inode,
 496                                 ((loff_t)(fofs + 1) << PAGE_CACHE_SHIFT));
 497         return 0;
 498 }
 499
 500 static int __allocate_data_blocks(struct inode *inode, loff_t offset,
 501                                                         size_t count)
 502 {
 503         struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
 504         struct dnode_of_data dn;
 505         u64 start = F2FS_BYTES_TO_BLK(offset);
 506         u64 len = F2FS_BYTES_TO_BLK(count);
 507         bool allocated;
 508         u64 end_offset;
 509         int err = 0;
 510
 511         while (len) {
 512                 f2fs_lock_op(sbi);
 513
 514                 /* When reading holes, we need its node page */
 515                 set_new_dnode(&dn, inode, NULL, NULL, 0);
 516                 err = get_dnode_of_data(&dn, start, ALLOC_NODE);
 517                 if (err)
 518                         goto out;
 519
 520                 allocated = false;
 521                 end_offset = ADDRS_PER_PAGE(dn.node_page, F2FS_I(inode));
 522
 523                 while (dn.ofs_in_node < end_offset && len) {
 524                         block_t blkaddr;
 525
 526                         if (unlikely(f2fs_cp_error(sbi))) {
 527                                 err = -EIO;
 528                                 goto sync_out;
 529                         }
 530
 531                         blkaddr = datablock_addr(dn.node_page, dn.ofs_in_node);
 532                         if (blkaddr == NULL_ADDR || blkaddr == NEW_ADDR) {
 533                                 err = __allocate_data_block(&dn);
 534                                 if (err)
 535                                         goto sync_out;
 536                                 allocated = true;
 537                         }
 538                         len--;
 539                         start++;
 540                         dn.ofs_in_node++;
 541                 }
 542
 543                 if (allocated)
 544                         sync_inode_page(&dn);
 545
 546                 f2fs_put_dnode(&dn);
 547                 f2fs_unlock_op(sbi);
 548
 549                 f2fs_balance_fs(sbi, dn.node_changed);
 550         }
 551         return err;
 552
 553 sync_out:
 554         if (allocated)
 555                 sync_inode_page(&dn);
 556         f2fs_put_dnode(&dn);
 557 out:
 558         f2fs_unlock_op(sbi);
 559         f2fs_balance_fs(sbi, dn.node_changed);
 560         return err;
 561 }
 562
 563 /*
 564  * f2fs_map_blocks() now supported readahead/bmap/rw direct_IO with
 565  * f2fs_map_blocks structure.
 566  * If original data blocks are allocated, then give them to blockdev.
 567  * Otherwise,
 568  *     a. preallocate requested block addresses
 569  *     b. do not use extent cache for better performance
 570  *     c. give the block addresses to blockdev
 571  */
 572 int f2fs_map_blocks(struct inode *inode, struct f2fs_map_blocks *map,
 573                                                 int create, int flag)
 574 {
 575         unsigned int maxblocks = map->m_len;
 576         struct dnode_of_data dn;
 577         struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
 578         int mode = create ? ALLOC_NODE : LOOKUP_NODE_RA;
 579         pgoff_t pgofs, end_offset;
 580         int err = 0, ofs = 1;
 581         struct extent_info ei;
 582         bool allocated = false;
 583         block_t blkaddr;
 584
 585         map->m_len = 0;
 586         map->m_flags = 0;
 587
 588         /* it only supports block size == page size */
 589         pgofs = (pgoff_t)map->m_lblk;
 590
 591         if (f2fs_lookup_extent_cache(inode, pgofs, &ei)) {
 592                 map->m_pblk = ei.blk + pgofs - ei.fofs;
 593                 map->m_len = min((pgoff_t)maxblocks, ei.fofs + ei.len - pgofs);
 594                 map->m_flags = F2FS_MAP_MAPPED;
 595                 goto out;
 596         }
 597
 598         if (create)
 599                 f2fs_lock_op(sbi);
 600
 601         /* When reading holes, we need its node page */
 602         set_new_dnode(&dn, inode, NULL, NULL, 0);
 603         err = get_dnode_of_data(&dn, pgofs, mode);
 604         if (err) {
 605                 if (err == -ENOENT)
 606                         err = 0;
 607                 goto unlock_out;
 608         }
 609
 610         if (dn.data_blkaddr == NEW_ADDR || dn.data_blkaddr == NULL_ADDR) {
 611                 if (create) {
 612                         if (unlikely(f2fs_cp_error(sbi))) {
 613                                 err = -EIO;
 614                                 goto put_out;
 615                         }
 616                         err = __allocate_data_block(&dn);
 617                         if (err)
 618                                 goto put_out;
 619                         allocated = true;
 620                         map->m_flags = F2FS_MAP_NEW;
 621                 } else {
 622                         if (flag != F2FS_GET_BLOCK_FIEMAP ||
 623                                                 dn.data_blkaddr != NEW_ADDR) {
 624                                 if (flag == F2FS_GET_BLOCK_BMAP)
 625                                         err = -ENOENT;
 626                                 goto put_out;
 627                         }
 628
 629                         /*
 630                          * preallocated unwritten block should be mapped
 631                          * for fiemap.
 632                          */
 633                         if (dn.data_blkaddr == NEW_ADDR)
 634                                 map->m_flags = F2FS_MAP_UNWRITTEN;
 635                 }
 636         }
 637
 638         map->m_flags |= F2FS_MAP_MAPPED;
 639         map->m_pblk = dn.data_blkaddr;
 640         map->m_len = 1;
 641
 642         end_offset = ADDRS_PER_PAGE(dn.node_page, F2FS_I(inode));
 643         dn.ofs_in_node++;
 644         pgofs++;
 645
 646 get_next:
 647         if (map->m_len >= maxblocks)
 648                 goto sync_out;
 649
 650         if (dn.ofs_in_node >= end_offset) {
 651                 if (allocated)
 652                         sync_inode_page(&dn);
 653                 allocated = false;
 654                 f2fs_put_dnode(&dn);
 655
 656                 if (create) {
 657                         f2fs_unlock_op(sbi);
 658                         f2fs_balance_fs(sbi, dn.node_changed);
 659                         f2fs_lock_op(sbi);
 660                 }
 661
 662                 set_new_dnode(&dn, inode, NULL, NULL, 0);
 663                 err = get_dnode_of_data(&dn, pgofs, mode);
 664                 if (err) {
 665                         if (err == -ENOENT)
 666                                 err = 0;
 667                         goto unlock_out;
 668                 }
 669
 670                 end_offset = ADDRS_PER_PAGE(dn.node_page, F2FS_I(inode));
 671         }
 672
 673         blkaddr = datablock_addr(dn.node_page, dn.ofs_in_node);
 674
 675         if (blkaddr == NEW_ADDR || blkaddr == NULL_ADDR) {
 676                 if (create) {
 677                         if (unlikely(f2fs_cp_error(sbi))) {
 678                                 err = -EIO;
 679                                 goto sync_out;
 680                         }
 681                         err = __allocate_data_block(&dn);
 682                         if (err)
 683                                 goto sync_out;
 684                         allocated = true;
 685                         map->m_flags |= F2FS_MAP_NEW;
 686                         blkaddr = dn.data_blkaddr;
 687                 } else {
 688                         /*
 689                          * we only merge preallocated unwritten blocks
 690                          * for fiemap.
 691                          */
 692                         if (flag != F2FS_GET_BLOCK_FIEMAP ||
 693                                         blkaddr != NEW_ADDR)
 694                                 goto sync_out;
 695                 }
 696         }
 697
 698         /* Give more consecutive addresses for the readahead */
 699         if ((map->m_pblk != NEW_ADDR &&
 700                         blkaddr == (map->m_pblk + ofs)) ||
 701                         (map->m_pblk == NEW_ADDR &&
 702                         blkaddr == NEW_ADDR)) {
 703                 ofs++;
 704                 dn.ofs_in_node++;
 705                 pgofs++;
 706                 map->m_len++;
 707                 goto get_next;
 708         }
 709
 710 sync_out:
 711         if (allocated)
 712                 sync_inode_page(&dn);
 713 put_out:
 714         f2fs_put_dnode(&dn);
 715 unlock_out:
 716         if (create) {
 717                 f2fs_unlock_op(sbi);
 718                 f2fs_balance_fs(sbi, dn.node_changed);
 719         }
 720 out:
 721         trace_f2fs_map_blocks(inode, map, err);
 722         return err;
 723 }
 724
 725 static int __get_data_block(struct inode *inode, sector_t iblock,
 726                         struct buffer_head *bh, int create, int flag)
 727 {
 728         struct f2fs_map_blocks map;
 729         int ret;
 730
 731         map.m_lblk = iblock;
 732         map.m_len = bh->b_size >> inode->i_blkbits;
 733
 734         ret = f2fs_map_blocks(inode, &map, create, flag);
 735         if (!ret) {
 736                 map_bh(bh, inode->i_sb, map.m_pblk);
 737                 bh->b_state = (bh->b_state & ~F2FS_MAP_FLAGS) | map.m_flags;
 738                 bh->b_size = map.m_len << inode->i_blkbits;
 739         }
 740         return ret;
 741 }
 742
 743 static int get_data_block(struct inode *inode, sector_t iblock,
 744                         struct buffer_head *bh_result, int create, int flag)
 745 {
 746         return __get_data_block(inode, iblock, bh_result, create, flag);
 747 }
 748
 749 static int get_data_block_dio(struct inode *inode, sector_t iblock,
 750                         struct buffer_head *bh_result, int create)
 751 {
 752         return __get_data_block(inode, iblock, bh_result, create,
 753                                                 F2FS_GET_BLOCK_DIO);
 754 }
 755
 756 static int get_data_block_bmap(struct inode *inode, sector_t iblock,
 757                         struct buffer_head *bh_result, int create)
 758 {
 759         /* Block number less than F2FS MAX BLOCKS */
 760         if (unlikely(iblock >= F2FS_I_SB(inode)->max_file_blocks))
 761                 return -EFBIG;
 762
 763         return __get_data_block(inode, iblock, bh_result, create,
 764                                                 F2FS_GET_BLOCK_BMAP);
 765 }
 766
 767 static inline sector_t logical_to_blk(struct inode *inode, loff_t offset)
 768 {
 769         return (offset >> inode->i_blkbits);
 770 }
 771
 772 static inline loff_t blk_to_logical(struct inode *inode, sector_t blk)
 773 {
 774         return (blk << inode->i_blkbits);
 775 }
 776
 777 int f2fs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
 778                 u64 start, u64 len)
 779 {
 780         struct buffer_head map_bh;
 781         sector_t start_blk, last_blk;
 782         loff_t isize;
 783         u64 logical = 0, phys = 0, size = 0;
 784         u32 flags = 0;
 785         int ret = 0;
 786
 787         ret = fiemap_check_flags(fieinfo, FIEMAP_FLAG_SYNC);
 788         if (ret)
 789                 return ret;
 790
 791         if (f2fs_has_inline_data(inode)) {
 792                 ret = f2fs_inline_data_fiemap(inode, fieinfo, start, len);
 793                 if (ret != -EAGAIN)
 794                         return ret;
 795         }
 796
 797         inode_lock(inode);
 798
 799         isize = i_size_read(inode);
 800         if (start >= isize)
 801                 goto out;
 802
 803         if (start + len > isize)
 804                 len = isize - start;
 805
 806         if (logical_to_blk(inode, len) == 0)
 807                 len = blk_to_logical(inode, 1);
 808
 809         start_blk = logical_to_blk(inode, start);
 810         last_blk = logical_to_blk(inode, start + len - 1);
 811
 812 next:
 813         memset(&map_bh, 0, sizeof(struct buffer_head));
 814         map_bh.b_size = len;
 815
 816         ret = get_data_block(inode, start_blk, &map_bh, 0,
 817                                         F2FS_GET_BLOCK_FIEMAP);
 818         if (ret)
 819                 goto out;
 820
 821         /* HOLE */
 822         if (!buffer_mapped(&map_bh)) {
 823                 /* Go through holes util pass the EOF */
 824                 if (blk_to_logical(inode, start_blk++) < isize)
 825                         goto prep_next;
 826                 /* Found a hole beyond isize means no more extents.
 827                  * Note that the premise is that filesystems don't
 828                  * punch holes beyond isize and keep size unchanged.
 829                  */
 830                 flags |= FIEMAP_EXTENT_LAST;
 831         }
 832
 833         if (size) {
 834                 if (f2fs_encrypted_inode(inode))
 835                         flags |= FIEMAP_EXTENT_DATA_ENCRYPTED;
 836
 837                 ret = fiemap_fill_next_extent(fieinfo, logical,
 838                                 phys, size, flags);
 839         }
 840
 841         if (start_blk > last_blk || ret)
 842                 goto out;
 843
 844         logical = blk_to_logical(inode, start_blk);
 845         phys = blk_to_logical(inode, map_bh.b_blocknr);
 846         size = map_bh.b_size;
 847         flags = 0;
 848         if (buffer_unwritten(&map_bh))
 849                 flags = FIEMAP_EXTENT_UNWRITTEN;
 850
 851         start_blk += logical_to_blk(inode, size);
 852
 853 prep_next:
 854         cond_resched();
 855         if (fatal_signal_pending(current))
 856                 ret = -EINTR;
 857         else
 858                 goto next;
 859 out:
 860         if (ret == 1)
 861                 ret = 0;
 862
 863         inode_unlock(inode);
 864         return ret;
 865 }
 866
 867 /*
 868  * This function was originally taken from fs/mpage.c, and customized for f2fs.
 869  * Major change was from block_size == page_size in f2fs by default.
 870  */
 871 static int f2fs_mpage_readpages(struct address_space *mapping,
 872                         struct list_head *pages, struct page *page,
 873                         unsigned nr_pages)
 874 {
 875         struct bio *bio = NULL;
 876         unsigned page_idx;
 877         sector_t last_block_in_bio = 0;
 878         struct inode *inode = mapping->host;
 879         const unsigned blkbits = inode->i_blkbits;
 880         const unsigned blocksize = 1 << blkbits;
 881         sector_t block_in_file;
 882         sector_t last_block;
 883         sector_t last_block_in_file;
 884         sector_t block_nr;
 885         struct block_device *bdev = inode->i_sb->s_bdev;
 886         struct f2fs_map_blocks map;
 887
 888         map.m_pblk = 0;
 889         map.m_lblk = 0;
 890         map.m_len = 0;
 891         map.m_flags = 0;
 892
 893         for (page_idx = 0; nr_pages; page_idx++, nr_pages--) {
 894
 895                 prefetchw(&page->flags);
 896                 if (pages) {
 897                         page = list_entry(pages->prev, struct page, lru);
 898                         list_del(&page->lru);
 899                         if (add_to_page_cache_lru(page, mapping,
 900                                                   page->index, GFP_KERNEL))
 901                                 goto next_page;
 902                 }
 903
 904                 block_in_file = (sector_t)page->index;
 905                 last_block = block_in_file + nr_pages;
 906                 last_block_in_file = (i_size_read(inode) + blocksize - 1) >>
 907                                                                 blkbits;
 908                 if (last_block > last_block_in_file)
 909                         last_block = last_block_in_file;
 910
 911                 /*
 912                  * Map blocks using the previous result first.
 913                  */
 914                 if ((map.m_flags & F2FS_MAP_MAPPED) &&
 915                                 block_in_file > map.m_lblk &&
 916                                 block_in_file < (map.m_lblk + map.m_len))
 917                         goto got_it;
 918
 919                 /*
 920                  * Then do more f2fs_map_blocks() calls until we are
 921                  * done with this page.
 922                  */
 923                 map.m_flags = 0;
 924
 925                 if (block_in_file < last_block) {
 926                         map.m_lblk = block_in_file;
 927                         map.m_len = last_block - block_in_file;
 928
 929                         if (f2fs_map_blocks(inode, &map, 0,
 930                                                         F2FS_GET_BLOCK_READ))
 931                                 goto set_error_page;
 932                 }
 933 got_it:
 934                 if ((map.m_flags & F2FS_MAP_MAPPED)) {
 935                         block_nr = map.m_pblk + block_in_file - map.m_lblk;
 936                         SetPageMappedToDisk(page);
 937
 938                         if (!PageUptodate(page) && !cleancache_get_page(page)) {
 939                                 SetPageUptodate(page);
 940                                 goto confused;
 941                         }
 942                 } else {
 943                         zero_user_segment(page, 0, PAGE_CACHE_SIZE);
 944                         SetPageUptodate(page);
 945                         unlock_page(page);
 946                         goto next_page;
 947                 }
 948
 949                 /*
 950                  * This page will go to BIO.  Do we need to send this
 951                  * BIO off first?
 952                  */
 953                 if (bio && (last_block_in_bio != block_nr - 1)) {
 954 submit_and_realloc:
 955                         submit_bio(READ, bio);
 956                         bio = NULL;
 957                 }
 958                 if (bio == NULL) {
 959                         struct f2fs_crypto_ctx *ctx = NULL;
 960
 961                         if (f2fs_encrypted_inode(inode) &&
 962                                         S_ISREG(inode->i_mode)) {
 963
 964                                 ctx = f2fs_get_crypto_ctx(inode);
 965                                 if (IS_ERR(ctx))
 966                                         goto set_error_page;
 967
 968                                 /* wait the page to be moved by cleaning */
 969                                 f2fs_wait_on_encrypted_page_writeback(
 970                                                 F2FS_I_SB(inode), block_nr);
 971                         }
 972
 973                         bio = bio_alloc(GFP_KERNEL,
 974                                 min_t(int, nr_pages, BIO_MAX_PAGES));
 975                         if (!bio) {
 976                                 if (ctx)
 977                                         f2fs_release_crypto_ctx(ctx);
 978                                 goto set_error_page;
 979                         }
 980                         bio->bi_bdev = bdev;
 981                         bio->bi_iter.bi_sector = SECTOR_FROM_BLOCK(block_nr);
 982                         bio->bi_end_io = f2fs_read_end_io;
 983                         bio->bi_private = ctx;
 984                 }
 985
 986                 if (bio_add_page(bio, page, blocksize, 0) < blocksize)
 987                         goto submit_and_realloc;
 988
 989                 last_block_in_bio = block_nr;
 990                 goto next_page;
 991 set_error_page:
 992                 SetPageError(page);
 993                 zero_user_segment(page, 0, PAGE_CACHE_SIZE);
 994                 unlock_page(page);
 995                 goto next_page;
 996 confused:
 997                 if (bio) {
 998                         submit_bio(READ, bio);
 999                         bio = NULL;
1000                 }
1001                 unlock_page(page);
1002 next_page:
1003                 if (pages)
1004                         page_cache_release(page);
1005         }
1006         BUG_ON(pages && !list_empty(pages));
1007         if (bio)
1008                 submit_bio(READ, bio);
1009         return 0;
1010 }
1011
1012 static int f2fs_read_data_page(struct file *file, struct page *page)
1013 {
1014         struct inode *inode = page->mapping->host;
1015         int ret = -EAGAIN;
1016
1017         trace_f2fs_readpage(page, DATA);
1018
1019         /* If the file has inline data, try to read it directly */
1020         if (f2fs_has_inline_data(inode))
1021                 ret = f2fs_read_inline_data(inode, page);
1022         if (ret == -EAGAIN)
1023                 ret = f2fs_mpage_readpages(page->mapping, NULL, page, 1);
1024         return ret;
1025 }
1026
1027 static int f2fs_read_data_pages(struct file *file,
1028                         struct address_space *mapping,
1029                         struct list_head *pages, unsigned nr_pages)
1030 {
1031         struct inode *inode = file->f_mapping->host;
1032         struct page *page = list_entry(pages->prev, struct page, lru);
1033
1034         trace_f2fs_readpages(inode, page, nr_pages);
1035
1036         /* If the file has inline data, skip readpages */
1037         if (f2fs_has_inline_data(inode))
1038                 return 0;
1039
1040         return f2fs_mpage_readpages(mapping, pages, NULL, nr_pages);
1041 }
1042
1043 int do_write_data_page(struct f2fs_io_info *fio)
1044 {
1045         struct page *page = fio->page;
1046         struct inode *inode = page->mapping->host;
1047         struct dnode_of_data dn;
1048         int err = 0;
1049
1050         set_new_dnode(&dn, inode, NULL, NULL, 0);
1051         err = get_dnode_of_data(&dn, page->index, LOOKUP_NODE);
1052         if (err)
1053                 return err;
1054
1055         fio->blk_addr = dn.data_blkaddr;
1056
1057         /* This page is already truncated */
1058         if (fio->blk_addr == NULL_ADDR) {
1059                 ClearPageUptodate(page);
1060                 goto out_writepage;
1061         }
1062
1063         if (f2fs_encrypted_inode(inode) && S_ISREG(inode->i_mode)) {
1064
1065                 /* wait for GCed encrypted page writeback */
1066                 f2fs_wait_on_encrypted_page_writeback(F2FS_I_SB(inode),
1067                                                         fio->blk_addr);
1068
1069                 fio->encrypted_page = f2fs_encrypt(inode, fio->page);
1070                 if (IS_ERR(fio->encrypted_page)) {
1071                         err = PTR_ERR(fio->encrypted_page);
1072                         goto out_writepage;
1073                 }
1074         }
1075
1076         set_page_writeback(page);
1077
1078         /*
1079          * If current allocation needs SSR,
1080          * it had better in-place writes for updated data.
1081          */
1082         if (unlikely(fio->blk_addr != NEW_ADDR &&
1083                         !is_cold_data(page) &&
1084                         !IS_ATOMIC_WRITTEN_PAGE(page) &&
1085                         need_inplace_update(inode))) {
1086                 rewrite_data_page(fio);
1087                 set_inode_flag(F2FS_I(inode), FI_UPDATE_WRITE);
1088                 trace_f2fs_do_write_data_page(page, IPU);
1089         } else {
1090                 write_data_page(&dn, fio);
1091                 set_data_blkaddr(&dn);
1092                 f2fs_update_extent_cache(&dn);
1093                 trace_f2fs_do_write_data_page(page, OPU);
1094                 set_inode_flag(F2FS_I(inode), FI_APPEND_WRITE);
1095                 if (page->index == 0)
1096                         set_inode_flag(F2FS_I(inode), FI_FIRST_BLOCK_WRITTEN);
1097         }
1098 out_writepage:
1099         f2fs_put_dnode(&dn);
1100         return err;
1101 }
1102
1103 static int f2fs_write_data_page(struct page *page,
1104                                         struct writeback_control *wbc)
1105 {
1106         struct inode *inode = page->mapping->host;
1107         struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
1108         loff_t i_size = i_size_read(inode);
1109         const pgoff_t end_index = ((unsigned long long) i_size)
1110                                                         >> PAGE_CACHE_SHIFT;
1111         unsigned offset = 0;
1112         bool need_balance_fs = false;
1113         int err = 0;
1114         struct f2fs_io_info fio = {
1115                 .sbi = sbi,
1116                 .type = DATA,
1117                 .rw = (wbc->sync_mode == WB_SYNC_ALL) ? WRITE_SYNC : WRITE,
1118                 .page = page,
1119                 .encrypted_page = NULL,
1120         };
1121
1122         trace_f2fs_writepage(page, DATA);
1123
1124         if (page->index < end_index)
1125                 goto write;
1126
1127         /*
1128          * If the offset is out-of-range of file size,
1129          * this page does not have to be written to disk.
1130          */
1131         offset = i_size & (PAGE_CACHE_SIZE - 1);
1132         if ((page->index >= end_index + 1) || !offset)
1133                 goto out;
1134
1135         zero_user_segment(page, offset, PAGE_CACHE_SIZE);
1136 write:
1137         if (unlikely(is_sbi_flag_set(sbi, SBI_POR_DOING)))
1138                 goto redirty_out;
1139         if (f2fs_is_drop_cache(inode))
1140                 goto out;
1141         if (f2fs_is_volatile_file(inode) && !wbc->for_reclaim &&
1142                         available_free_memory(sbi, BASE_CHECK))
1143                 goto redirty_out;
1144
1145         /* Dentry blocks are controlled by checkpoint */
1146         if (S_ISDIR(inode->i_mode)) {
1147                 if (unlikely(f2fs_cp_error(sbi)))
1148                         goto redirty_out;
1149                 err = do_write_data_page(&fio);
1150                 goto done;
1151         }
1152
1153         /* we should bypass data pages to proceed the kworkder jobs */
1154         if (unlikely(f2fs_cp_error(sbi))) {
1155                 SetPageError(page);
1156                 goto out;
1157         }
1158
1159         if (!wbc->for_reclaim)
1160                 need_balance_fs = true;
1161         else if (has_not_enough_free_secs(sbi, 0))
1162                 goto redirty_out;
1163
1164         err = -EAGAIN;
1165         f2fs_lock_op(sbi);
1166         if (f2fs_has_inline_data(inode))
1167                 err = f2fs_write_inline_data(inode, page);
1168         if (err == -EAGAIN)
1169                 err = do_write_data_page(&fio);
1170         f2fs_unlock_op(sbi);
1171 done:
1172         if (err && err != -ENOENT)
1173                 goto redirty_out;
1174
1175         clear_cold_data(page);
1176 out:
1177         inode_dec_dirty_pages(inode);
1178         if (err)
1179                 ClearPageUptodate(page);
1180         unlock_page(page);
1181         f2fs_balance_fs(sbi, need_balance_fs);
1182         if (wbc->for_reclaim || unlikely(f2fs_cp_error(sbi))) {
1183                 f2fs_submit_merged_bio(sbi, DATA, WRITE);
1184                 remove_dirty_inode(inode);
1185         }
1186         return 0;
1187
1188 redirty_out:
1189         redirty_page_for_writepage(wbc, page);
1190         return AOP_WRITEPAGE_ACTIVATE;
1191 }
1192
1193 static int __f2fs_writepage(struct page *page, struct writeback_control *wbc,
1194                         void *data)
1195 {
1196         struct address_space *mapping = data;
1197         int ret = mapping->a_ops->writepage(page, wbc);
1198         mapping_set_error(mapping, ret);
1199         return ret;
1200 }
1201
1202 /*
1203  * This function was copied from write_cche_pages from mm/page-writeback.c.
1204  * The major change is making write step of cold data page separately from
1205  * warm/hot data page.
1206  */
1207 static int f2fs_write_cache_pages(struct address_space *mapping,
1208                         struct writeback_control *wbc, writepage_t writepage,
1209                         void *data)
1210 {
1211         int ret = 0;
1212         int done = 0;
1213         struct pagevec pvec;
1214         int nr_pages;
1215         pgoff_t uninitialized_var(writeback_index);
1216         pgoff_t index;
1217         pgoff_t end;            /* Inclusive */
1218         pgoff_t done_index;
1219         int cycled;
1220         int range_whole = 0;
1221         int tag;
1222         int step = 0;
1223
1224         pagevec_init(&pvec, 0);
1225 next:
1226         if (wbc->range_cyclic) {
1227                 writeback_index = mapping->writeback_index; /* prev offset */
1228                 index = writeback_index;
1229                 if (index == 0)
1230                         cycled = 1;
1231                 else
1232                         cycled = 0;
1233                 end = -1;
1234         } else {
1235                 index = wbc->range_start >> PAGE_CACHE_SHIFT;
1236                 end = wbc->range_end >> PAGE_CACHE_SHIFT;
1237                 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
1238                         range_whole = 1;
1239                 cycled = 1; /* ignore range_cyclic tests */
1240         }
1241         if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)
1242                 tag = PAGECACHE_TAG_TOWRITE;
1243         else
1244                 tag = PAGECACHE_TAG_DIRTY;
1245 retry:
1246         if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)
1247                 tag_pages_for_writeback(mapping, index, end);
1248         done_index = index;
1249         while (!done && (index <= end)) {
1250                 int i;
1251
1252                 nr_pages = pagevec_lookup_tag(&pvec, mapping, &index, tag,
1253                               min(end - index, (pgoff_t)PAGEVEC_SIZE - 1) + 1);
1254                 if (nr_pages == 0)
1255                         break;
1256
1257                 for (i = 0; i < nr_pages; i++) {
1258                         struct page *page = pvec.pages[i];
1259
1260                         if (page->index > end) {
1261                                 done = 1;
1262                                 break;
1263                         }
1264
1265                         done_index = page->index;
1266
1267                         lock_page(page);
1268
1269                         if (unlikely(page->mapping != mapping)) {
1270 continue_unlock:
1271                                 unlock_page(page);
1272                                 continue;
1273                         }
1274
1275                         if (!PageDirty(page)) {
1276                                 /* someone wrote it for us */
1277                                 goto continue_unlock;
1278                         }
1279
1280                         if (step == is_cold_data(page))
1281                                 goto continue_unlock;
1282
1283                         if (PageWriteback(page)) {
1284                                 if (wbc->sync_mode != WB_SYNC_NONE)
1285                                         f2fs_wait_on_page_writeback(page, DATA);
1286                                 else
1287                                         goto continue_unlock;
1288                         }
1289
1290                         BUG_ON(PageWriteback(page));
1291                         if (!clear_page_dirty_for_io(page))
1292                                 goto continue_unlock;
1293
1294                         ret = (*writepage)(page, wbc, data);
1295                         if (unlikely(ret)) {
1296                                 if (ret == AOP_WRITEPAGE_ACTIVATE) {
1297                                         unlock_page(page);
1298                                         ret = 0;
1299                                 } else {
1300                                         done_index = page->index + 1;
1301                                         done = 1;
1302                                         break;
1303                                 }
1304                         }
1305
1306                         if (--wbc->nr_to_write <= 0 &&
1307                             wbc->sync_mode == WB_SYNC_NONE) {
1308                                 done = 1;
1309                                 break;
1310                         }
1311                 }
1312                 pagevec_release(&pvec);
1313                 cond_resched();
1314         }
1315
1316         if (step < 1) {
1317                 step++;
1318                 goto next;
1319         }
1320
1321         if (!cycled && !done) {
1322                 cycled = 1;
1323                 index = 0;
1324                 end = writeback_index - 1;
1325                 goto retry;
1326         }
1327         if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
1328                 mapping->writeback_index = done_index;
1329
1330         return ret;
1331 }
1332
1333 static int f2fs_write_data_pages(struct address_space *mapping,
1334                             struct writeback_control *wbc)
1335 {
1336         struct inode *inode = mapping->host;
1337         struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
1338         bool locked = false;
1339         int ret;
1340         long diff;
1341
1342         trace_f2fs_writepages(mapping->host, wbc, DATA);
1343
1344         /* deal with chardevs and other special file */
1345         if (!mapping->a_ops->writepage)
1346                 return 0;
1347
1348         /* skip writing if there is no dirty page in this inode */
1349         if (!get_dirty_pages(inode) && wbc->sync_mode == WB_SYNC_NONE)
1350                 return 0;
1351
1352         if (S_ISDIR(inode->i_mode) && wbc->sync_mode == WB_SYNC_NONE &&
1353                         get_dirty_pages(inode) < nr_pages_to_skip(sbi, DATA) &&
1354                         available_free_memory(sbi, DIRTY_DENTS))
1355                 goto skip_write;
1356
1357         /* skip writing during file defragment */
1358         if (is_inode_flag_set(F2FS_I(inode), FI_DO_DEFRAG))
1359                 goto skip_write;
1360
1361         /* during POR, we don't need to trigger writepage at all. */
1362         if (unlikely(is_sbi_flag_set(sbi, SBI_POR_DOING)))
1363                 goto skip_write;
1364
1365         diff = nr_pages_to_write(sbi, DATA, wbc);
1366
1367         if (!S_ISDIR(inode->i_mode)) {
1368                 mutex_lock(&sbi->writepages);
1369                 locked = true;
1370         }
1371         ret = f2fs_write_cache_pages(mapping, wbc, __f2fs_writepage, mapping);
1372         f2fs_submit_merged_bio(sbi, DATA, WRITE);
1373         if (locked)
1374                 mutex_unlock(&sbi->writepages);
1375
1376         remove_dirty_inode(inode);
1377
1378         wbc->nr_to_write = max((long)0, wbc->nr_to_write - diff);
1379         return ret;
1380
1381 skip_write:
1382         wbc->pages_skipped += get_dirty_pages(inode);
1383         return 0;
1384 }
1385
1386 static void f2fs_write_failed(struct address_space *mapping, loff_t to)
1387 {
1388         struct inode *inode = mapping->host;
1389         loff_t i_size = i_size_read(inode);
1390
1391         if (to > i_size) {
1392                 truncate_pagecache(inode, i_size);
1393                 truncate_blocks(inode, i_size, true);
1394         }
1395 }
1396
1397 static int prepare_write_begin(struct f2fs_sb_info *sbi,
1398                         struct page *page, loff_t pos, unsigned len,
1399                         block_t *blk_addr, bool *node_changed)
1400 {
1401         struct inode *inode = page->mapping->host;
1402         pgoff_t index = page->index;
1403         struct dnode_of_data dn;
1404         struct page *ipage;
1405         bool locked = false;
1406         struct extent_info ei;
1407         int err = 0;
1408
1409         if (f2fs_has_inline_data(inode) ||
1410                         (pos & PAGE_CACHE_MASK) >= i_size_read(inode)) {
1411                 f2fs_lock_op(sbi);
1412                 locked = true;
1413         }
1414 restart:
1415         /* check inline_data */
1416         ipage = get_node_page(sbi, inode->i_ino);
1417         if (IS_ERR(ipage)) {
1418                 err = PTR_ERR(ipage);
1419                 goto unlock_out;
1420         }
1421
1422         set_new_dnode(&dn, inode, ipage, ipage, 0);
1423
1424         if (f2fs_has_inline_data(inode)) {
1425                 if (pos + len <= MAX_INLINE_DATA) {
1426                         read_inline_data(page, ipage);
1427                         set_inode_flag(F2FS_I(inode), FI_DATA_EXIST);
1428                         sync_inode_page(&dn);
1429                 } else {
1430                         err = f2fs_convert_inline_page(&dn, page);
1431                         if (err)
1432                                 goto out;
1433                         if (dn.data_blkaddr == NULL_ADDR)
1434                                 err = f2fs_get_block(&dn, index);
1435                 }
1436         } else if (locked) {
1437                 err = f2fs_get_block(&dn, index);
1438         } else {
1439                 if (f2fs_lookup_extent_cache(inode, index, &ei)) {
1440                         dn.data_blkaddr = ei.blk + index - ei.fofs;
1441                 } else {
1442                         bool restart = false;
1443
1444                         /* hole case */
1445                         err = get_dnode_of_data(&dn, index, LOOKUP_NODE);
1446                         if (err || (!err && dn.data_blkaddr == NULL_ADDR))
1447                                 restart = true;
1448                         if (restart) {
1449                                 f2fs_put_dnode(&dn);
1450                                 f2fs_lock_op(sbi);
1451                                 locked = true;
1452                                 goto restart;
1453                         }
1454                 }
1455         }
1456
1457         /* convert_inline_page can make node_changed */
1458         *blk_addr = dn.data_blkaddr;
1459         *node_changed = dn.node_changed;
1460 out:
1461         f2fs_put_dnode(&dn);
1462 unlock_out:
1463         if (locked)
1464                 f2fs_unlock_op(sbi);
1465         return err;
1466 }
1467
1468 static int f2fs_write_begin(struct file *file, struct address_space *mapping,
1469                 loff_t pos, unsigned len, unsigned flags,
1470                 struct page **pagep, void **fsdata)
1471 {
1472         struct inode *inode = mapping->host;
1473         struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
1474         struct page *page = NULL;
1475         pgoff_t index = ((unsigned long long) pos) >> PAGE_CACHE_SHIFT;
1476         bool need_balance = false;
1477         block_t blkaddr = NULL_ADDR;
1478         int err = 0;
1479
1480         trace_f2fs_write_begin(inode, pos, len, flags);
1481
1482         /*
1483          * We should check this at this moment to avoid deadlock on inode page
1484          * and #0 page. The locking rule for inline_data conversion should be:
1485          * lock_page(page #0) -> lock_page(inode_page)
1486          */
1487         if (index != 0) {
1488                 err = f2fs_convert_inline_inode(inode);
1489                 if (err)
1490                         goto fail;
1491         }
1492 repeat:
1493         page = grab_cache_page_write_begin(mapping, index, flags);
1494         if (!page) {
1495                 err = -ENOMEM;
1496                 goto fail;
1497         }
1498
1499         *pagep = page;
1500
1501         err = prepare_write_begin(sbi, page, pos, len,
1502                                         &blkaddr, &need_balance);
1503         if (err)
1504                 goto fail;
1505
1506         if (need_balance && has_not_enough_free_secs(sbi, 0)) {
1507                 unlock_page(page);
1508                 f2fs_balance_fs(sbi, true);
1509                 lock_page(page);
1510                 if (page->mapping != mapping) {
1511                         /* The page got truncated from under us */
1512                         f2fs_put_page(page, 1);
1513                         goto repeat;
1514                 }
1515         }
1516
1517         f2fs_wait_on_page_writeback(page, DATA);
1518
1519         /* wait for GCed encrypted page writeback */
1520         if (f2fs_encrypted_inode(inode) && S_ISREG(inode->i_mode))
1521                 f2fs_wait_on_encrypted_page_writeback(sbi, blkaddr);
1522
1523         if (len == PAGE_CACHE_SIZE)
1524                 goto out_update;
1525         if (PageUptodate(page))
1526                 goto out_clear;
1527
1528         if ((pos & PAGE_CACHE_MASK) >= i_size_read(inode)) {
1529                 unsigned start = pos & (PAGE_CACHE_SIZE - 1);
1530                 unsigned end = start + len;
1531
1532                 /* Reading beyond i_size is simple: memset to zero */
1533                 zero_user_segments(page, 0, start, end, PAGE_CACHE_SIZE);
1534                 goto out_update;
1535         }
1536
1537         if (blkaddr == NEW_ADDR) {
1538                 zero_user_segment(page, 0, PAGE_CACHE_SIZE);
1539         } else {
1540                 struct f2fs_io_info fio = {
1541                         .sbi = sbi,
1542                         .type = DATA,
1543                         .rw = READ_SYNC,
1544                         .blk_addr = blkaddr,
1545                         .page = page,
1546                         .encrypted_page = NULL,
1547                 };
1548                 err = f2fs_submit_page_bio(&fio);
1549                 if (err)
1550                         goto fail;
1551
1552                 lock_page(page);
1553                 if (unlikely(!PageUptodate(page))) {
1554                         err = -EIO;
1555                         goto fail;
1556                 }
1557                 if (unlikely(page->mapping != mapping)) {
1558                         f2fs_put_page(page, 1);
1559                         goto repeat;
1560                 }
1561
1562                 /* avoid symlink page */
1563                 if (f2fs_encrypted_inode(inode) && S_ISREG(inode->i_mode)) {
1564                         err = f2fs_decrypt_one(inode, page);
1565                         if (err)
1566                                 goto fail;
1567                 }
1568         }
1569 out_update:
1570         SetPageUptodate(page);
1571 out_clear:
1572         clear_cold_data(page);
1573         return 0;
1574
1575 fail:
1576         f2fs_put_page(page, 1);
1577         f2fs_write_failed(mapping, pos + len);
1578         return err;
1579 }
1580
1581 static int f2fs_write_end(struct file *file,
1582                         struct address_space *mapping,
1583                         loff_t pos, unsigned len, unsigned copied,
1584                         struct page *page, void *fsdata)
1585 {
1586         struct inode *inode = page->mapping->host;
1587
1588         trace_f2fs_write_end(inode, pos, len, copied);
1589
1590         set_page_dirty(page);
1591
1592         if (pos + copied > i_size_read(inode)) {
1593                 i_size_write(inode, pos + copied);
1594                 mark_inode_dirty(inode);
1595                 update_inode_page(inode);
1596         }
1597
1598         f2fs_put_page(page, 1);
1599         f2fs_update_time(F2FS_I_SB(inode), REQ_TIME);
1600         return copied;
1601 }
1602
1603 static int check_direct_IO(struct inode *inode, struct iov_iter *iter,
1604                            loff_t offset)
1605 {
1606         unsigned blocksize_mask = inode->i_sb->s_blocksize - 1;
1607
1608         if (offset & blocksize_mask)
1609                 return -EINVAL;
1610
1611         if (iov_iter_alignment(iter) & blocksize_mask)
1612                 return -EINVAL;
1613
1614         return 0;
1615 }
1616
1617 static ssize_t f2fs_direct_IO(struct kiocb *iocb, struct iov_iter *iter,
1618                               loff_t offset)
1619 {
1620         struct file *file = iocb->ki_filp;
1621         struct address_space *mapping = file->f_mapping;
1622         struct inode *inode = mapping->host;
1623         size_t count = iov_iter_count(iter);
1624         int err;
1625
1626         /* we don't need to use inline_data strictly */
1627         err = f2fs_convert_inline_inode(inode);
1628         if (err)
1629                 return err;
1630
1631         if (f2fs_encrypted_inode(inode) && S_ISREG(inode->i_mode))
1632                 return 0;
1633
1634         err = check_direct_IO(inode, iter, offset);
1635         if (err)
1636                 return err;
1637
1638         trace_f2fs_direct_IO_enter(inode, offset, count, iov_iter_rw(iter));
1639
1640         if (iov_iter_rw(iter) == WRITE) {
1641                 err = __allocate_data_blocks(inode, offset, count);
1642                 if (err)
1643                         goto out;
1644         }
1645
1646         err = blockdev_direct_IO(iocb, inode, iter, offset, get_data_block_dio);
1647 out:
1648         if (err < 0 && iov_iter_rw(iter) == WRITE)
1649                 f2fs_write_failed(mapping, offset + count);
1650
1651         trace_f2fs_direct_IO_exit(inode, offset, count, iov_iter_rw(iter), err);
1652
1653         return err;
1654 }
1655
1656 void f2fs_invalidate_page(struct page *page, unsigned int offset,
1657                                                         unsigned int length)
1658 {
1659         struct inode *inode = page->mapping->host;
1660         struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
1661
1662         if (inode->i_ino >= F2FS_ROOT_INO(sbi) &&
1663                 (offset % PAGE_CACHE_SIZE || length != PAGE_CACHE_SIZE))
1664                 return;
1665
1666         if (PageDirty(page)) {
1667                 if (inode->i_ino == F2FS_META_INO(sbi))
1668                         dec_page_count(sbi, F2FS_DIRTY_META);
1669                 else if (inode->i_ino == F2FS_NODE_INO(sbi))
1670                         dec_page_count(sbi, F2FS_DIRTY_NODES);
1671                 else
1672                         inode_dec_dirty_pages(inode);
1673         }
1674
1675         /* This is atomic written page, keep Private */
1676         if (IS_ATOMIC_WRITTEN_PAGE(page))
1677                 return;
1678
1679         ClearPagePrivate(page);
1680 }
1681
1682 int f2fs_release_page(struct page *page, gfp_t wait)
1683 {
1684         /* If this is dirty page, keep PagePrivate */
1685         if (PageDirty(page))
1686                 return 0;
1687
1688         /* This is atomic written page, keep Private */
1689         if (IS_ATOMIC_WRITTEN_PAGE(page))
1690                 return 0;
1691
1692         ClearPagePrivate(page);
1693         return 1;
1694 }
1695
1696 static int f2fs_set_data_page_dirty(struct page *page)
1697 {
1698         struct address_space *mapping = page->mapping;
1699         struct inode *inode = mapping->host;
1700
1701         trace_f2fs_set_page_dirty(page, DATA);
1702
1703         SetPageUptodate(page);
1704
1705         if (f2fs_is_atomic_file(inode)) {
1706                 if (!IS_ATOMIC_WRITTEN_PAGE(page)) {
1707                         register_inmem_page(inode, page);
1708                         return 1;
1709                 }
1710                 /*
1711                  * Previously, this page has been registered, we just
1712                  * return here.
1713                  */
1714                 return 0;
1715         }
1716
1717         if (!PageDirty(page)) {
1718                 __set_page_dirty_nobuffers(page);
1719                 update_dirty_page(inode, page);
1720                 return 1;
1721         }
1722         return 0;
1723 }
1724
1725 static sector_t f2fs_bmap(struct address_space *mapping, sector_t block)
1726 {
1727         struct inode *inode = mapping->host;
1728
1729         if (f2fs_has_inline_data(inode))
1730                 return 0;
1731
1732         /* make sure allocating whole blocks */
1733         if (mapping_tagged(mapping, PAGECACHE_TAG_DIRTY))
1734                 filemap_write_and_wait(mapping);
1735
1736         return generic_block_bmap(mapping, block, get_data_block_bmap);
1737 }
1738
1739 const struct address_space_operations f2fs_dblock_aops = {
1740         .readpage       = f2fs_read_data_page,
1741         .readpages      = f2fs_read_data_pages,
1742         .writepage      = f2fs_write_data_page,
1743         .writepages     = f2fs_write_data_pages,
1744         .write_begin    = f2fs_write_begin,
1745         .write_end      = f2fs_write_end,
1746         .set_page_dirty = f2fs_set_data_page_dirty,
1747         .invalidatepage = f2fs_invalidate_page,
1748         .releasepage    = f2fs_release_page,
1749         .direct_IO      = f2fs_direct_IO,
1750         .bmap           = f2fs_bmap,
1751 };