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         set_page_dirty(node_page);
 229 }
 230
 231 int reserve_new_block(struct dnode_of_data *dn)
 232 {
 233         struct f2fs_sb_info *sbi = F2FS_I_SB(dn->inode);
 234
 235         if (unlikely(is_inode_flag_set(F2FS_I(dn->inode), FI_NO_ALLOC)))
 236                 return -EPERM;
 237         if (unlikely(!inc_valid_block_count(sbi, dn->inode, 1)))
 238                 return -ENOSPC;
 239
 240         trace_f2fs_reserve_new_block(dn->inode, dn->nid, dn->ofs_in_node);
 241
 242         dn->data_blkaddr = NEW_ADDR;
 243         set_data_blkaddr(dn);
 244         mark_inode_dirty(dn->inode);
 245         sync_inode_page(dn);
 246         return 0;
 247 }
 248
 249 int f2fs_reserve_block(struct dnode_of_data *dn, pgoff_t index)
 250 {
 251         bool need_put = dn->inode_page ? false : true;
 252         int err;
 253
 254         err = get_dnode_of_data(dn, index, ALLOC_NODE);
 255         if (err)
 256                 return err;
 257
 258         if (dn->data_blkaddr == NULL_ADDR)
 259                 err = reserve_new_block(dn);
 260         if (err || need_put)
 261                 f2fs_put_dnode(dn);
 262         return err;
 263 }
 264
 265 int f2fs_get_block(struct dnode_of_data *dn, pgoff_t index)
 266 {
 267         struct extent_info ei;
 268         struct inode *inode = dn->inode;
 269
 270         if (f2fs_lookup_extent_cache(inode, index, &ei)) {
 271                 dn->data_blkaddr = ei.blk + index - ei.fofs;
 272                 return 0;
 273         }
 274
 275         return f2fs_reserve_block(dn, index);
 276 }
 277
 278 struct page *get_read_data_page(struct inode *inode, pgoff_t index,
 279                                                 int rw, bool for_write)
 280 {
 281         struct address_space *mapping = inode->i_mapping;
 282         struct dnode_of_data dn;
 283         struct page *page;
 284         struct extent_info ei;
 285         int err;
 286         struct f2fs_io_info fio = {
 287                 .sbi = F2FS_I_SB(inode),
 288                 .type = DATA,
 289                 .rw = rw,
 290                 .encrypted_page = NULL,
 291         };
 292
 293         if (f2fs_encrypted_inode(inode) && S_ISREG(inode->i_mode))
 294                 return read_mapping_page(mapping, index, NULL);
 295
 296         page = f2fs_grab_cache_page(mapping, index, for_write);
 297         if (!page)
 298                 return ERR_PTR(-ENOMEM);
 299
 300         if (f2fs_lookup_extent_cache(inode, index, &ei)) {
 301                 dn.data_blkaddr = ei.blk + index - ei.fofs;
 302                 goto got_it;
 303         }
 304
 305         set_new_dnode(&dn, inode, NULL, NULL, 0);
 306         err = get_dnode_of_data(&dn, index, LOOKUP_NODE);
 307         if (err)
 308                 goto put_err;
 309         f2fs_put_dnode(&dn);
 310
 311         if (unlikely(dn.data_blkaddr == NULL_ADDR)) {
 312                 err = -ENOENT;
 313                 goto put_err;
 314         }
 315 got_it:
 316         if (PageUptodate(page)) {
 317                 unlock_page(page);
 318                 return page;
 319         }
 320
 321         /*
 322          * A new dentry page is allocated but not able to be written, since its
 323          * new inode page couldn't be allocated due to -ENOSPC.
 324          * In such the case, its blkaddr can be remained as NEW_ADDR.
 325          * see, f2fs_add_link -> get_new_data_page -> init_inode_metadata.
 326          */
 327         if (dn.data_blkaddr == NEW_ADDR) {
 328                 zero_user_segment(page, 0, PAGE_CACHE_SIZE);
 329                 SetPageUptodate(page);
 330                 unlock_page(page);
 331                 return page;
 332         }
 333
 334         fio.blk_addr = dn.data_blkaddr;
 335         fio.page = page;
 336         err = f2fs_submit_page_bio(&fio);
 337         if (err)
 338                 goto put_err;
 339         return page;
 340
 341 put_err:
 342         f2fs_put_page(page, 1);
 343         return ERR_PTR(err);
 344 }
 345
 346 struct page *find_data_page(struct inode *inode, pgoff_t index)
 347 {
 348         struct address_space *mapping = inode->i_mapping;
 349         struct page *page;
 350
 351         page = find_get_page(mapping, index);
 352         if (page && PageUptodate(page))
 353                 return page;
 354         f2fs_put_page(page, 0);
 355
 356         page = get_read_data_page(inode, index, READ_SYNC, false);
 357         if (IS_ERR(page))
 358                 return page;
 359
 360         if (PageUptodate(page))
 361                 return page;
 362
 363         wait_on_page_locked(page);
 364         if (unlikely(!PageUptodate(page))) {
 365                 f2fs_put_page(page, 0);
 366                 return ERR_PTR(-EIO);
 367         }
 368         return page;
 369 }
 370
 371 /*
 372  * If it tries to access a hole, return an error.
 373  * Because, the callers, functions in dir.c and GC, should be able to know
 374  * whether this page exists or not.
 375  */
 376 struct page *get_lock_data_page(struct inode *inode, pgoff_t index,
 377                                                         bool for_write)
 378 {
 379         struct address_space *mapping = inode->i_mapping;
 380         struct page *page;
 381 repeat:
 382         page = get_read_data_page(inode, index, READ_SYNC, for_write);
 383         if (IS_ERR(page))
 384                 return page;
 385
 386         /* wait for read completion */
 387         lock_page(page);
 388         if (unlikely(!PageUptodate(page))) {
 389                 f2fs_put_page(page, 1);
 390                 return ERR_PTR(-EIO);
 391         }
 392         if (unlikely(page->mapping != mapping)) {
 393                 f2fs_put_page(page, 1);
 394                 goto repeat;
 395         }
 396         return page;
 397 }
 398
 399 /*
 400  * Caller ensures that this data page is never allocated.
 401  * A new zero-filled data page is allocated in the page cache.
 402  *
 403  * Also, caller should grab and release a rwsem by calling f2fs_lock_op() and
 404  * f2fs_unlock_op().
 405  * Note that, ipage is set only by make_empty_dir, and if any error occur,
 406  * ipage should be released by this function.
 407  */
 408 struct page *get_new_data_page(struct inode *inode,
 409                 struct page *ipage, pgoff_t index, bool new_i_size)
 410 {
 411         struct address_space *mapping = inode->i_mapping;
 412         struct page *page;
 413         struct dnode_of_data dn;
 414         int err;
 415 repeat:
 416         page = f2fs_grab_cache_page(mapping, index, true);
 417         if (!page) {
 418                 /*
 419                  * before exiting, we should make sure ipage will be released
 420                  * if any error occur.
 421                  */
 422                 f2fs_put_page(ipage, 1);
 423                 return ERR_PTR(-ENOMEM);
 424         }
 425
 426         set_new_dnode(&dn, inode, ipage, NULL, 0);
 427         err = f2fs_reserve_block(&dn, index);
 428         if (err) {
 429                 f2fs_put_page(page, 1);
 430                 return ERR_PTR(err);
 431         }
 432         if (!ipage)
 433                 f2fs_put_dnode(&dn);
 434
 435         if (PageUptodate(page))
 436                 goto got_it;
 437
 438         if (dn.data_blkaddr == NEW_ADDR) {
 439                 zero_user_segment(page, 0, PAGE_CACHE_SIZE);
 440                 SetPageUptodate(page);
 441         } else {
 442                 f2fs_put_page(page, 1);
 443
 444                 page = get_read_data_page(inode, index, READ_SYNC, true);
 445                 if (IS_ERR(page))
 446                         goto repeat;
 447
 448                 /* wait for read completion */
 449                 lock_page(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
 498         /* direct IO doesn't use extent cache to maximize the performance */
 499         f2fs_drop_largest_extent(dn->inode, fofs);
 500
 501         return 0;
 502 }
 503
 504 static void __allocate_data_blocks(struct inode *inode, loff_t offset,
 505                                                         size_t count)
 506 {
 507         struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
 508         struct dnode_of_data dn;
 509         u64 start = F2FS_BYTES_TO_BLK(offset);
 510         u64 len = F2FS_BYTES_TO_BLK(count);
 511         bool allocated;
 512         u64 end_offset;
 513
 514         while (len) {
 515                 f2fs_balance_fs(sbi);
 516                 f2fs_lock_op(sbi);
 517
 518                 /* When reading holes, we need its node page */
 519                 set_new_dnode(&dn, inode, NULL, NULL, 0);
 520                 if (get_dnode_of_data(&dn, start, ALLOC_NODE))
 521                         goto out;
 522
 523                 allocated = false;
 524                 end_offset = ADDRS_PER_PAGE(dn.node_page, F2FS_I(inode));
 525
 526                 while (dn.ofs_in_node < end_offset && len) {
 527                         block_t blkaddr;
 528
 529                         if (unlikely(f2fs_cp_error(sbi)))
 530                                 goto sync_out;
 531
 532                         blkaddr = datablock_addr(dn.node_page, dn.ofs_in_node);
 533                         if (blkaddr == NULL_ADDR || blkaddr == NEW_ADDR) {
 534                                 if (__allocate_data_block(&dn))
 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         return;
 550
 551 sync_out:
 552         if (allocated)
 553                 sync_inode_page(&dn);
 554         f2fs_put_dnode(&dn);
 555 out:
 556         f2fs_unlock_op(sbi);
 557         return;
 558 }
 559
 560 /*
 561  * f2fs_map_blocks() now supported readahead/bmap/rw direct_IO with
 562  * f2fs_map_blocks structure.
 563  * If original data blocks are allocated, then give them to blockdev.
 564  * Otherwise,
 565  *     a. preallocate requested block addresses
 566  *     b. do not use extent cache for better performance
 567  *     c. give the block addresses to blockdev
 568  */
 569 static int f2fs_map_blocks(struct inode *inode, struct f2fs_map_blocks *map,
 570                                                 int create, int flag)
 571 {
 572         unsigned int maxblocks = map->m_len;
 573         struct dnode_of_data dn;
 574         struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
 575         int mode = create ? ALLOC_NODE : LOOKUP_NODE_RA;
 576         pgoff_t pgofs, end_offset;
 577         int err = 0, ofs = 1;
 578         struct extent_info ei;
 579         bool allocated = false;
 580
 581         map->m_len = 0;
 582         map->m_flags = 0;
 583
 584         /* it only supports block size == page size */
 585         pgofs = (pgoff_t)map->m_lblk;
 586
 587         if (f2fs_lookup_extent_cache(inode, pgofs, &ei)) {
 588                 map->m_pblk = ei.blk + pgofs - ei.fofs;
 589                 map->m_len = min((pgoff_t)maxblocks, ei.fofs + ei.len - pgofs);
 590                 map->m_flags = F2FS_MAP_MAPPED;
 591                 goto out;
 592         }
 593
 594         if (create)
 595                 f2fs_lock_op(F2FS_I_SB(inode));
 596
 597         /* When reading holes, we need its node page */
 598         set_new_dnode(&dn, inode, NULL, NULL, 0);
 599         err = get_dnode_of_data(&dn, pgofs, mode);
 600         if (err) {
 601                 if (err == -ENOENT)
 602                         err = 0;
 603                 goto unlock_out;
 604         }
 605
 606         if (dn.data_blkaddr == NEW_ADDR || dn.data_blkaddr == NULL_ADDR) {
 607                 if (create) {
 608                         if (unlikely(f2fs_cp_error(sbi))) {
 609                                 err = -EIO;
 610                                 goto put_out;
 611                         }
 612                         err = __allocate_data_block(&dn);
 613                         if (err)
 614                                 goto put_out;
 615                         allocated = true;
 616                         map->m_flags = F2FS_MAP_NEW;
 617                 } else {
 618                         if (flag != F2FS_GET_BLOCK_FIEMAP ||
 619                                                 dn.data_blkaddr != NEW_ADDR) {
 620                                 if (flag == F2FS_GET_BLOCK_BMAP)
 621                                         err = -ENOENT;
 622                                 goto put_out;
 623                         }
 624
 625                         /*
 626                          * preallocated unwritten block should be mapped
 627                          * for fiemap.
 628                          */
 629                         if (dn.data_blkaddr == NEW_ADDR)
 630                                 map->m_flags = F2FS_MAP_UNWRITTEN;
 631                 }
 632         }
 633
 634         map->m_flags |= F2FS_MAP_MAPPED;
 635         map->m_pblk = dn.data_blkaddr;
 636         map->m_len = 1;
 637
 638         end_offset = ADDRS_PER_PAGE(dn.node_page, F2FS_I(inode));
 639         dn.ofs_in_node++;
 640         pgofs++;
 641
 642 get_next:
 643         if (dn.ofs_in_node >= end_offset) {
 644                 if (allocated)
 645                         sync_inode_page(&dn);
 646                 allocated = false;
 647                 f2fs_put_dnode(&dn);
 648
 649                 set_new_dnode(&dn, inode, NULL, NULL, 0);
 650                 err = get_dnode_of_data(&dn, pgofs, mode);
 651                 if (err) {
 652                         if (err == -ENOENT)
 653                                 err = 0;
 654                         goto unlock_out;
 655                 }
 656
 657                 end_offset = ADDRS_PER_PAGE(dn.node_page, F2FS_I(inode));
 658         }
 659
 660         if (maxblocks > map->m_len) {
 661                 block_t blkaddr = datablock_addr(dn.node_page, dn.ofs_in_node);
 662
 663                 if (blkaddr == NEW_ADDR || blkaddr == NULL_ADDR) {
 664                         if (create) {
 665                                 if (unlikely(f2fs_cp_error(sbi))) {
 666                                         err = -EIO;
 667                                         goto sync_out;
 668                                 }
 669                                 err = __allocate_data_block(&dn);
 670                                 if (err)
 671                                         goto sync_out;
 672                                 allocated = true;
 673                                 map->m_flags |= F2FS_MAP_NEW;
 674                                 blkaddr = dn.data_blkaddr;
 675                         } else {
 676                                 /*
 677                                  * we only merge preallocated unwritten blocks
 678                                  * for fiemap.
 679                                  */
 680                                 if (flag != F2FS_GET_BLOCK_FIEMAP ||
 681                                                 blkaddr != NEW_ADDR)
 682                                         goto sync_out;
 683                         }
 684                 }
 685
 686                 /* Give more consecutive addresses for the readahead */
 687                 if ((map->m_pblk != NEW_ADDR &&
 688                                 blkaddr == (map->m_pblk + ofs)) ||
 689                                 (map->m_pblk == NEW_ADDR &&
 690                                 blkaddr == NEW_ADDR)) {
 691                         ofs++;
 692                         dn.ofs_in_node++;
 693                         pgofs++;
 694                         map->m_len++;
 695                         goto get_next;
 696                 }
 697         }
 698 sync_out:
 699         if (allocated)
 700                 sync_inode_page(&dn);
 701 put_out:
 702         f2fs_put_dnode(&dn);
 703 unlock_out:
 704         if (create)
 705                 f2fs_unlock_op(F2FS_I_SB(inode));
 706 out:
 707         trace_f2fs_map_blocks(inode, map, err);
 708         return err;
 709 }
 710
 711 static int __get_data_block(struct inode *inode, sector_t iblock,
 712                         struct buffer_head *bh, int create, int flag)
 713 {
 714         struct f2fs_map_blocks map;
 715         int ret;
 716
 717         map.m_lblk = iblock;
 718         map.m_len = bh->b_size >> inode->i_blkbits;
 719
 720         ret = f2fs_map_blocks(inode, &map, create, flag);
 721         if (!ret) {
 722                 map_bh(bh, inode->i_sb, map.m_pblk);
 723                 bh->b_state = (bh->b_state & ~F2FS_MAP_FLAGS) | map.m_flags;
 724                 bh->b_size = map.m_len << inode->i_blkbits;
 725         }
 726         return ret;
 727 }
 728
 729 static int get_data_block(struct inode *inode, sector_t iblock,
 730                         struct buffer_head *bh_result, int create, int flag)
 731 {
 732         return __get_data_block(inode, iblock, bh_result, create, flag);
 733 }
 734
 735 static int get_data_block_dio(struct inode *inode, sector_t iblock,
 736                         struct buffer_head *bh_result, int create)
 737 {
 738         return __get_data_block(inode, iblock, bh_result, create,
 739                                                 F2FS_GET_BLOCK_DIO);
 740 }
 741
 742 static int get_data_block_bmap(struct inode *inode, sector_t iblock,
 743                         struct buffer_head *bh_result, int create)
 744 {
 745         return __get_data_block(inode, iblock, bh_result, create,
 746                                                 F2FS_GET_BLOCK_BMAP);
 747 }
 748
 749 static inline sector_t logical_to_blk(struct inode *inode, loff_t offset)
 750 {
 751         return (offset >> inode->i_blkbits);
 752 }
 753
 754 static inline loff_t blk_to_logical(struct inode *inode, sector_t blk)
 755 {
 756         return (blk << inode->i_blkbits);
 757 }
 758
 759 int f2fs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
 760                 u64 start, u64 len)
 761 {
 762         struct buffer_head map_bh;
 763         sector_t start_blk, last_blk;
 764         loff_t isize = i_size_read(inode);
 765         u64 logical = 0, phys = 0, size = 0;
 766         u32 flags = 0;
 767         bool past_eof = false, whole_file = false;
 768         int ret = 0;
 769
 770         ret = fiemap_check_flags(fieinfo, FIEMAP_FLAG_SYNC);
 771         if (ret)
 772                 return ret;
 773
 774         if (f2fs_has_inline_data(inode)) {
 775                 ret = f2fs_inline_data_fiemap(inode, fieinfo, start, len);
 776                 if (ret != -EAGAIN)
 777                         return ret;
 778         }
 779
 780         mutex_lock(&inode->i_mutex);
 781
 782         if (len >= isize) {
 783                 whole_file = true;
 784                 len = isize;
 785         }
 786
 787         if (logical_to_blk(inode, len) == 0)
 788                 len = blk_to_logical(inode, 1);
 789
 790         start_blk = logical_to_blk(inode, start);
 791         last_blk = logical_to_blk(inode, start + len - 1);
 792 next:
 793         memset(&map_bh, 0, sizeof(struct buffer_head));
 794         map_bh.b_size = len;
 795
 796         ret = get_data_block(inode, start_blk, &map_bh, 0,
 797                                         F2FS_GET_BLOCK_FIEMAP);
 798         if (ret)
 799                 goto out;
 800
 801         /* HOLE */
 802         if (!buffer_mapped(&map_bh)) {
 803                 start_blk++;
 804
 805                 if (!past_eof && blk_to_logical(inode, start_blk) >= isize)
 806                         past_eof = 1;
 807
 808                 if (past_eof && size) {
 809                         flags |= FIEMAP_EXTENT_LAST;
 810                         ret = fiemap_fill_next_extent(fieinfo, logical,
 811                                         phys, size, flags);
 812                 } else if (size) {
 813                         ret = fiemap_fill_next_extent(fieinfo, logical,
 814                                         phys, size, flags);
 815                         size = 0;
 816                 }
 817
 818                 /* if we have holes up to/past EOF then we're done */
 819                 if (start_blk > last_blk || past_eof || ret)
 820                         goto out;
 821         } else {
 822                 if (start_blk > last_blk && !whole_file) {
 823                         ret = fiemap_fill_next_extent(fieinfo, logical,
 824                                         phys, size, flags);
 825                         goto out;
 826                 }
 827
 828                 /*
 829                  * if size != 0 then we know we already have an extent
 830                  * to add, so add it.
 831                  */
 832                 if (size) {
 833                         ret = fiemap_fill_next_extent(fieinfo, logical,
 834                                         phys, size, flags);
 835                         if (ret)
 836                                 goto out;
 837                 }
 838
 839                 logical = blk_to_logical(inode, start_blk);
 840                 phys = blk_to_logical(inode, map_bh.b_blocknr);
 841                 size = map_bh.b_size;
 842                 flags = 0;
 843                 if (buffer_unwritten(&map_bh))
 844                         flags = FIEMAP_EXTENT_UNWRITTEN;
 845
 846                 start_blk += logical_to_blk(inode, size);
 847
 848                 /*
 849                  * If we are past the EOF, then we need to make sure as
 850                  * soon as we find a hole that the last extent we found
 851                  * is marked with FIEMAP_EXTENT_LAST
 852                  */
 853                 if (!past_eof && logical + size >= isize)
 854                         past_eof = true;
 855         }
 856         cond_resched();
 857         if (fatal_signal_pending(current))
 858                 ret = -EINTR;
 859         else
 860                 goto next;
 861 out:
 862         if (ret == 1)
 863                 ret = 0;
 864
 865         mutex_unlock(&inode->i_mutex);
 866         return ret;
 867 }
 868
 869 /*
 870  * This function was originally taken from fs/mpage.c, and customized for f2fs.
 871  * Major change was from block_size == page_size in f2fs by default.
 872  */
 873 static int f2fs_mpage_readpages(struct address_space *mapping,
 874                         struct list_head *pages, struct page *page,
 875                         unsigned nr_pages)
 876 {
 877         struct bio *bio = NULL;
 878         unsigned page_idx;
 879         sector_t last_block_in_bio = 0;
 880         struct inode *inode = mapping->host;
 881         const unsigned blkbits = inode->i_blkbits;
 882         const unsigned blocksize = 1 << blkbits;
 883         sector_t block_in_file;
 884         sector_t last_block;
 885         sector_t last_block_in_file;
 886         sector_t block_nr;
 887         struct block_device *bdev = inode->i_sb->s_bdev;
 888         struct f2fs_map_blocks map;
 889
 890         map.m_pblk = 0;
 891         map.m_lblk = 0;
 892         map.m_len = 0;
 893         map.m_flags = 0;
 894
 895         for (page_idx = 0; nr_pages; page_idx++, nr_pages--) {
 896
 897                 prefetchw(&page->flags);
 898                 if (pages) {
 899                         page = list_entry(pages->prev, struct page, lru);
 900                         list_del(&page->lru);
 901                         if (add_to_page_cache_lru(page, mapping,
 902                                                   page->index, GFP_KERNEL))
 903                                 goto next_page;
 904                 }
 905
 906                 block_in_file = (sector_t)page->index;
 907                 last_block = block_in_file + nr_pages;
 908                 last_block_in_file = (i_size_read(inode) + blocksize - 1) >>
 909                                                                 blkbits;
 910                 if (last_block > last_block_in_file)
 911                         last_block = last_block_in_file;
 912
 913                 /*
 914                  * Map blocks using the previous result first.
 915                  */
 916                 if ((map.m_flags & F2FS_MAP_MAPPED) &&
 917                                 block_in_file > map.m_lblk &&
 918                                 block_in_file < (map.m_lblk + map.m_len))
 919                         goto got_it;
 920
 921                 /*
 922                  * Then do more f2fs_map_blocks() calls until we are
 923                  * done with this page.
 924                  */
 925                 map.m_flags = 0;
 926
 927                 if (block_in_file < last_block) {
 928                         map.m_lblk = block_in_file;
 929                         map.m_len = last_block - block_in_file;
 930
 931                         if (f2fs_map_blocks(inode, &map, 0,
 932                                                         F2FS_GET_BLOCK_READ))
 933                                 goto set_error_page;
 934                 }
 935 got_it:
 936                 if ((map.m_flags & F2FS_MAP_MAPPED)) {
 937                         block_nr = map.m_pblk + block_in_file - map.m_lblk;
 938                         SetPageMappedToDisk(page);
 939
 940                         if (!PageUptodate(page) && !cleancache_get_page(page)) {
 941                                 SetPageUptodate(page);
 942                                 goto confused;
 943                         }
 944                 } else {
 945                         zero_user_segment(page, 0, PAGE_CACHE_SIZE);
 946                         SetPageUptodate(page);
 947                         unlock_page(page);
 948                         goto next_page;
 949                 }
 950
 951                 /*
 952                  * This page will go to BIO.  Do we need to send this
 953                  * BIO off first?
 954                  */
 955                 if (bio && (last_block_in_bio != block_nr - 1)) {
 956 submit_and_realloc:
 957                         submit_bio(READ, bio);
 958                         bio = NULL;
 959                 }
 960                 if (bio == NULL) {
 961                         struct f2fs_crypto_ctx *ctx = NULL;
 962
 963                         if (f2fs_encrypted_inode(inode) &&
 964                                         S_ISREG(inode->i_mode)) {
 965
 966                                 ctx = f2fs_get_crypto_ctx(inode);
 967                                 if (IS_ERR(ctx))
 968                                         goto set_error_page;
 969
 970                                 /* wait the page to be moved by cleaning */
 971                                 f2fs_wait_on_encrypted_page_writeback(
 972                                                 F2FS_I_SB(inode), block_nr);
 973                         }
 974
 975                         bio = bio_alloc(GFP_KERNEL,
 976                                 min_t(int, nr_pages, BIO_MAX_PAGES));
 977                         if (!bio) {
 978                                 if (ctx)
 979                                         f2fs_release_crypto_ctx(ctx);
 980                                 goto set_error_page;
 981                         }
 982                         bio->bi_bdev = bdev;
 983                         bio->bi_iter.bi_sector = SECTOR_FROM_BLOCK(block_nr);
 984                         bio->bi_end_io = f2fs_read_end_io;
 985                         bio->bi_private = ctx;
 986                 }
 987
 988                 if (bio_add_page(bio, page, blocksize, 0) < blocksize)
 989                         goto submit_and_realloc;
 990
 991                 last_block_in_bio = block_nr;
 992                 goto next_page;
 993 set_error_page:
 994                 SetPageError(page);
 995                 zero_user_segment(page, 0, PAGE_CACHE_SIZE);
 996                 unlock_page(page);
 997                 goto next_page;
 998 confused:
 999                 if (bio) {
1000                         submit_bio(READ, bio);
1001                         bio = NULL;
1002                 }
1003                 unlock_page(page);
1004 next_page:
1005                 if (pages)
1006                         page_cache_release(page);
1007         }
1008         BUG_ON(pages && !list_empty(pages));
1009         if (bio)
1010                 submit_bio(READ, bio);
1011         return 0;
1012 }
1013
1014 static int f2fs_read_data_page(struct file *file, struct page *page)
1015 {
1016         struct inode *inode = page->mapping->host;
1017         int ret = -EAGAIN;
1018
1019         trace_f2fs_readpage(page, DATA);
1020
1021         /* If the file has inline data, try to read it directly */
1022         if (f2fs_has_inline_data(inode))
1023                 ret = f2fs_read_inline_data(inode, page);
1024         if (ret == -EAGAIN)
1025                 ret = f2fs_mpage_readpages(page->mapping, NULL, page, 1);
1026         return ret;
1027 }
1028
1029 static int f2fs_read_data_pages(struct file *file,
1030                         struct address_space *mapping,
1031                         struct list_head *pages, unsigned nr_pages)
1032 {
1033         struct inode *inode = file->f_mapping->host;
1034         struct page *page = list_entry(pages->prev, struct page, lru);
1035
1036         trace_f2fs_readpages(inode, page, nr_pages);
1037
1038         /* If the file has inline data, skip readpages */
1039         if (f2fs_has_inline_data(inode))
1040                 return 0;
1041
1042         return f2fs_mpage_readpages(mapping, pages, NULL, nr_pages);
1043 }
1044
1045 int do_write_data_page(struct f2fs_io_info *fio)
1046 {
1047         struct page *page = fio->page;
1048         struct inode *inode = page->mapping->host;
1049         struct dnode_of_data dn;
1050         int err = 0;
1051
1052         set_new_dnode(&dn, inode, NULL, NULL, 0);
1053         err = get_dnode_of_data(&dn, page->index, LOOKUP_NODE);
1054         if (err)
1055                 return err;
1056
1057         fio->blk_addr = dn.data_blkaddr;
1058
1059         /* This page is already truncated */
1060         if (fio->blk_addr == NULL_ADDR) {
1061                 ClearPageUptodate(page);
1062                 goto out_writepage;
1063         }
1064
1065         if (f2fs_encrypted_inode(inode) && S_ISREG(inode->i_mode)) {
1066
1067                 /* wait for GCed encrypted page writeback */
1068                 f2fs_wait_on_encrypted_page_writeback(F2FS_I_SB(inode),
1069                                                         fio->blk_addr);
1070
1071                 fio->encrypted_page = f2fs_encrypt(inode, fio->page);
1072                 if (IS_ERR(fio->encrypted_page)) {
1073                         err = PTR_ERR(fio->encrypted_page);
1074                         goto out_writepage;
1075                 }
1076         }
1077
1078         set_page_writeback(page);
1079
1080         /*
1081          * If current allocation needs SSR,
1082          * it had better in-place writes for updated data.
1083          */
1084         if (unlikely(fio->blk_addr != NEW_ADDR &&
1085                         !is_cold_data(page) &&
1086                         need_inplace_update(inode))) {
1087                 rewrite_data_page(fio);
1088                 set_inode_flag(F2FS_I(inode), FI_UPDATE_WRITE);
1089                 trace_f2fs_do_write_data_page(page, IPU);
1090         } else {
1091                 write_data_page(&dn, fio);
1092                 set_data_blkaddr(&dn);
1093                 f2fs_update_extent_cache(&dn);
1094                 trace_f2fs_do_write_data_page(page, OPU);
1095                 set_inode_flag(F2FS_I(inode), FI_APPEND_WRITE);
1096                 if (page->index == 0)
1097                         set_inode_flag(F2FS_I(inode), FI_FIRST_BLOCK_WRITTEN);
1098         }
1099 out_writepage:
1100         f2fs_put_dnode(&dn);
1101         return err;
1102 }
1103
1104 static int f2fs_write_data_page(struct page *page,
1105                                         struct writeback_control *wbc)
1106 {
1107         struct inode *inode = page->mapping->host;
1108         struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
1109         loff_t i_size = i_size_read(inode);
1110         const pgoff_t end_index = ((unsigned long long) i_size)
1111                                                         >> PAGE_CACHE_SHIFT;
1112         unsigned offset = 0;
1113         bool need_balance_fs = false;
1114         int err = 0;
1115         struct f2fs_io_info fio = {
1116                 .sbi = sbi,
1117                 .type = DATA,
1118                 .rw = (wbc->sync_mode == WB_SYNC_ALL) ? WRITE_SYNC : WRITE,
1119                 .page = page,
1120                 .encrypted_page = NULL,
1121         };
1122
1123         trace_f2fs_writepage(page, DATA);
1124
1125         if (page->index < end_index)
1126                 goto write;
1127
1128         /*
1129          * If the offset is out-of-range of file size,
1130          * this page does not have to be written to disk.
1131          */
1132         offset = i_size & (PAGE_CACHE_SIZE - 1);
1133         if ((page->index >= end_index + 1) || !offset)
1134                 goto out;
1135
1136         zero_user_segment(page, offset, PAGE_CACHE_SIZE);
1137 write:
1138         if (unlikely(is_sbi_flag_set(sbi, SBI_POR_DOING)))
1139                 goto redirty_out;
1140         if (f2fs_is_drop_cache(inode))
1141                 goto out;
1142         if (f2fs_is_volatile_file(inode) && !wbc->for_reclaim &&
1143                         available_free_memory(sbi, BASE_CHECK))
1144                 goto redirty_out;
1145
1146         /* Dentry blocks are controlled by checkpoint */
1147         if (S_ISDIR(inode->i_mode)) {
1148                 if (unlikely(f2fs_cp_error(sbi)))
1149                         goto redirty_out;
1150                 err = do_write_data_page(&fio);
1151                 goto done;
1152         }
1153
1154         /* we should bypass data pages to proceed the kworkder jobs */
1155         if (unlikely(f2fs_cp_error(sbi))) {
1156                 SetPageError(page);
1157                 goto out;
1158         }
1159
1160         if (!wbc->for_reclaim)
1161                 need_balance_fs = true;
1162         else if (has_not_enough_free_secs(sbi, 0))
1163                 goto redirty_out;
1164
1165         err = -EAGAIN;
1166         f2fs_lock_op(sbi);
1167         if (f2fs_has_inline_data(inode))
1168                 err = f2fs_write_inline_data(inode, page);
1169         if (err == -EAGAIN)
1170                 err = do_write_data_page(&fio);
1171         f2fs_unlock_op(sbi);
1172 done:
1173         if (err && err != -ENOENT)
1174                 goto redirty_out;
1175
1176         clear_cold_data(page);
1177 out:
1178         inode_dec_dirty_pages(inode);
1179         if (err)
1180                 ClearPageUptodate(page);
1181         unlock_page(page);
1182         if (need_balance_fs)
1183                 f2fs_balance_fs(sbi);
1184         if (wbc->for_reclaim)
1185                 f2fs_submit_merged_bio(sbi, DATA, WRITE);
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         /* during POR, we don't need to trigger writepage at all. */
1358         if (unlikely(is_sbi_flag_set(sbi, SBI_POR_DOING)))
1359                 goto skip_write;
1360
1361         diff = nr_pages_to_write(sbi, DATA, wbc);
1362
1363         if (!S_ISDIR(inode->i_mode)) {
1364                 mutex_lock(&sbi->writepages);
1365                 locked = true;
1366         }
1367         ret = f2fs_write_cache_pages(mapping, wbc, __f2fs_writepage, mapping);
1368         f2fs_submit_merged_bio(sbi, DATA, WRITE);
1369         if (locked)
1370                 mutex_unlock(&sbi->writepages);
1371
1372         remove_dirty_dir_inode(inode);
1373
1374         wbc->nr_to_write = max((long)0, wbc->nr_to_write - diff);
1375         return ret;
1376
1377 skip_write:
1378         wbc->pages_skipped += get_dirty_pages(inode);
1379         return 0;
1380 }
1381
1382 static void f2fs_write_failed(struct address_space *mapping, loff_t to)
1383 {
1384         struct inode *inode = mapping->host;
1385
1386         if (to > inode->i_size) {
1387                 truncate_pagecache(inode, inode->i_size);
1388                 truncate_blocks(inode, inode->i_size, true);
1389         }
1390 }
1391
1392 static int f2fs_write_begin(struct file *file, struct address_space *mapping,
1393                 loff_t pos, unsigned len, unsigned flags,
1394                 struct page **pagep, void **fsdata)
1395 {
1396         struct inode *inode = mapping->host;
1397         struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
1398         struct page *page = NULL;
1399         struct page *ipage;
1400         pgoff_t index = ((unsigned long long) pos) >> PAGE_CACHE_SHIFT;
1401         struct dnode_of_data dn;
1402         int err = 0;
1403
1404         trace_f2fs_write_begin(inode, pos, len, flags);
1405
1406         f2fs_balance_fs(sbi);
1407
1408         /*
1409          * We should check this at this moment to avoid deadlock on inode page
1410          * and #0 page. The locking rule for inline_data conversion should be:
1411          * lock_page(page #0) -> lock_page(inode_page)
1412          */
1413         if (index != 0) {
1414                 err = f2fs_convert_inline_inode(inode);
1415                 if (err)
1416                         goto fail;
1417         }
1418 repeat:
1419         page = grab_cache_page_write_begin(mapping, index, flags);
1420         if (!page) {
1421                 err = -ENOMEM;
1422                 goto fail;
1423         }
1424
1425         *pagep = page;
1426
1427         f2fs_lock_op(sbi);
1428
1429         /* check inline_data */
1430         ipage = get_node_page(sbi, inode->i_ino);
1431         if (IS_ERR(ipage)) {
1432                 err = PTR_ERR(ipage);
1433                 goto unlock_fail;
1434         }
1435
1436         set_new_dnode(&dn, inode, ipage, ipage, 0);
1437
1438         if (f2fs_has_inline_data(inode)) {
1439                 if (pos + len <= MAX_INLINE_DATA) {
1440                         read_inline_data(page, ipage);
1441                         set_inode_flag(F2FS_I(inode), FI_DATA_EXIST);
1442                         sync_inode_page(&dn);
1443                         goto put_next;
1444                 }
1445                 err = f2fs_convert_inline_page(&dn, page);
1446                 if (err)
1447                         goto put_fail;
1448         }
1449
1450         err = f2fs_get_block(&dn, index);
1451         if (err)
1452                 goto put_fail;
1453 put_next:
1454         f2fs_put_dnode(&dn);
1455         f2fs_unlock_op(sbi);
1456
1457         f2fs_wait_on_page_writeback(page, DATA);
1458
1459         /* wait for GCed encrypted page writeback */
1460         if (f2fs_encrypted_inode(inode) && S_ISREG(inode->i_mode))
1461                 f2fs_wait_on_encrypted_page_writeback(sbi, dn.data_blkaddr);
1462
1463         if (len == PAGE_CACHE_SIZE)
1464                 goto out_update;
1465         if (PageUptodate(page))
1466                 goto out_clear;
1467
1468         if ((pos & PAGE_CACHE_MASK) >= i_size_read(inode)) {
1469                 unsigned start = pos & (PAGE_CACHE_SIZE - 1);
1470                 unsigned end = start + len;
1471
1472                 /* Reading beyond i_size is simple: memset to zero */
1473                 zero_user_segments(page, 0, start, end, PAGE_CACHE_SIZE);
1474                 goto out_update;
1475         }
1476
1477         if (dn.data_blkaddr == NEW_ADDR) {
1478                 zero_user_segment(page, 0, PAGE_CACHE_SIZE);
1479         } else {
1480                 struct f2fs_io_info fio = {
1481                         .sbi = sbi,
1482                         .type = DATA,
1483                         .rw = READ_SYNC,
1484                         .blk_addr = dn.data_blkaddr,
1485                         .page = page,
1486                         .encrypted_page = NULL,
1487                 };
1488                 err = f2fs_submit_page_bio(&fio);
1489                 if (err)
1490                         goto fail;
1491
1492                 lock_page(page);
1493                 if (unlikely(!PageUptodate(page))) {
1494                         err = -EIO;
1495                         goto fail;
1496                 }
1497                 if (unlikely(page->mapping != mapping)) {
1498                         f2fs_put_page(page, 1);
1499                         goto repeat;
1500                 }
1501
1502                 /* avoid symlink page */
1503                 if (f2fs_encrypted_inode(inode) && S_ISREG(inode->i_mode)) {
1504                         err = f2fs_decrypt_one(inode, page);
1505                         if (err)
1506                                 goto fail;
1507                 }
1508         }
1509 out_update:
1510         SetPageUptodate(page);
1511 out_clear:
1512         clear_cold_data(page);
1513         return 0;
1514
1515 put_fail:
1516         f2fs_put_dnode(&dn);
1517 unlock_fail:
1518         f2fs_unlock_op(sbi);
1519 fail:
1520         f2fs_put_page(page, 1);
1521         f2fs_write_failed(mapping, pos + len);
1522         return err;
1523 }
1524
1525 static int f2fs_write_end(struct file *file,
1526                         struct address_space *mapping,
1527                         loff_t pos, unsigned len, unsigned copied,
1528                         struct page *page, void *fsdata)
1529 {
1530         struct inode *inode = page->mapping->host;
1531
1532         trace_f2fs_write_end(inode, pos, len, copied);
1533
1534         set_page_dirty(page);
1535
1536         if (pos + copied > i_size_read(inode)) {
1537                 i_size_write(inode, pos + copied);
1538                 mark_inode_dirty(inode);
1539                 update_inode_page(inode);
1540         }
1541
1542         f2fs_put_page(page, 1);
1543         return copied;
1544 }
1545
1546 static int check_direct_IO(struct inode *inode, struct iov_iter *iter,
1547                            loff_t offset)
1548 {
1549         unsigned blocksize_mask = inode->i_sb->s_blocksize - 1;
1550
1551         if (offset & blocksize_mask)
1552                 return -EINVAL;
1553
1554         if (iov_iter_alignment(iter) & blocksize_mask)
1555                 return -EINVAL;
1556
1557         return 0;
1558 }
1559
1560 static ssize_t f2fs_direct_IO(struct kiocb *iocb, struct iov_iter *iter,
1561                               loff_t offset)
1562 {
1563         struct file *file = iocb->ki_filp;
1564         struct address_space *mapping = file->f_mapping;
1565         struct inode *inode = mapping->host;
1566         size_t count = iov_iter_count(iter);
1567         int err;
1568
1569         /* we don't need to use inline_data strictly */
1570         if (f2fs_has_inline_data(inode)) {
1571                 err = f2fs_convert_inline_inode(inode);
1572                 if (err)
1573                         return err;
1574         }
1575
1576         if (f2fs_encrypted_inode(inode) && S_ISREG(inode->i_mode))
1577                 return 0;
1578
1579         err = check_direct_IO(inode, iter, offset);
1580         if (err)
1581                 return err;
1582
1583         trace_f2fs_direct_IO_enter(inode, offset, count, iov_iter_rw(iter));
1584
1585         if (iov_iter_rw(iter) == WRITE) {
1586                 __allocate_data_blocks(inode, offset, count);
1587                 if (unlikely(f2fs_cp_error(F2FS_I_SB(inode)))) {
1588                         err = -EIO;
1589                         goto out;
1590                 }
1591         }
1592
1593         err = blockdev_direct_IO(iocb, inode, iter, offset, get_data_block_dio);
1594 out:
1595         if (err < 0 && iov_iter_rw(iter) == WRITE)
1596                 f2fs_write_failed(mapping, offset + count);
1597
1598         trace_f2fs_direct_IO_exit(inode, offset, count, iov_iter_rw(iter), err);
1599
1600         return err;
1601 }
1602
1603 void f2fs_invalidate_page(struct page *page, unsigned int offset,
1604                                                         unsigned int length)
1605 {
1606         struct inode *inode = page->mapping->host;
1607         struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
1608
1609         if (inode->i_ino >= F2FS_ROOT_INO(sbi) &&
1610                 (offset % PAGE_CACHE_SIZE || length != PAGE_CACHE_SIZE))
1611                 return;
1612
1613         if (PageDirty(page)) {
1614                 if (inode->i_ino == F2FS_META_INO(sbi))
1615                         dec_page_count(sbi, F2FS_DIRTY_META);
1616                 else if (inode->i_ino == F2FS_NODE_INO(sbi))
1617                         dec_page_count(sbi, F2FS_DIRTY_NODES);
1618                 else
1619                         inode_dec_dirty_pages(inode);
1620         }
1621
1622         /* This is atomic written page, keep Private */
1623         if (IS_ATOMIC_WRITTEN_PAGE(page))
1624                 return;
1625
1626         ClearPagePrivate(page);
1627 }
1628
1629 int f2fs_release_page(struct page *page, gfp_t wait)
1630 {
1631         /* If this is dirty page, keep PagePrivate */
1632         if (PageDirty(page))
1633                 return 0;
1634
1635         /* This is atomic written page, keep Private */
1636         if (IS_ATOMIC_WRITTEN_PAGE(page))
1637                 return 0;
1638
1639         ClearPagePrivate(page);
1640         return 1;
1641 }
1642
1643 static int f2fs_set_data_page_dirty(struct page *page)
1644 {
1645         struct address_space *mapping = page->mapping;
1646         struct inode *inode = mapping->host;
1647
1648         trace_f2fs_set_page_dirty(page, DATA);
1649
1650         SetPageUptodate(page);
1651
1652         if (f2fs_is_atomic_file(inode)) {
1653                 if (!IS_ATOMIC_WRITTEN_PAGE(page)) {
1654                         register_inmem_page(inode, page);
1655                         return 1;
1656                 }
1657                 /*
1658                  * Previously, this page has been registered, we just
1659                  * return here.
1660                  */
1661                 return 0;
1662         }
1663
1664         if (!PageDirty(page)) {
1665                 __set_page_dirty_nobuffers(page);
1666                 update_dirty_page(inode, page);
1667                 return 1;
1668         }
1669         return 0;
1670 }
1671
1672 static sector_t f2fs_bmap(struct address_space *mapping, sector_t block)
1673 {
1674         struct inode *inode = mapping->host;
1675
1676         if (f2fs_has_inline_data(inode))
1677                 return 0;
1678
1679         /* make sure allocating whole blocks */
1680         if (mapping_tagged(mapping, PAGECACHE_TAG_DIRTY))
1681                 filemap_write_and_wait(mapping);
1682
1683         return generic_block_bmap(mapping, block, get_data_block_bmap);
1684 }
1685
1686 const struct address_space_operations f2fs_dblock_aops = {
1687         .readpage       = f2fs_read_data_page,
1688         .readpages      = f2fs_read_data_pages,
1689         .writepage      = f2fs_write_data_page,
1690         .writepages     = f2fs_write_data_pages,
1691         .write_begin    = f2fs_write_begin,
1692         .write_end      = f2fs_write_end,
1693         .set_page_dirty = f2fs_set_data_page_dirty,
1694         .invalidatepage = f2fs_invalidate_page,
1695         .releasepage    = f2fs_release_page,
1696         .direct_IO      = f2fs_direct_IO,
1697         .bmap           = f2fs_bmap,
1698 };