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/mm.h>
  23 #include <linux/memcontrol.h>
  24 #include <linux/cleancache.h>
  25
  26 #include "f2fs.h"
  27 #include "node.h"
  28 #include "segment.h"
  29 #include "trace.h"
  30 #include <trace/events/f2fs.h>
  31
  32 static bool __is_cp_guaranteed(struct page *page)
  33 {
  34         struct address_space *mapping = page->mapping;
  35         struct inode *inode;
  36         struct f2fs_sb_info *sbi;
  37
  38         if (!mapping)
  39                 return false;
  40
  41         inode = mapping->host;
  42         sbi = F2FS_I_SB(inode);
  43
  44         if (inode->i_ino == F2FS_META_INO(sbi) ||
  45                         inode->i_ino ==  F2FS_NODE_INO(sbi) ||
  46                         S_ISDIR(inode->i_mode) ||
  47                         is_cold_data(page))
  48                 return true;
  49         return false;
  50 }
  51
  52 static void f2fs_read_end_io(struct bio *bio)
  53 {
  54         struct bio_vec *bvec;
  55         int i;
  56
  57 #ifdef CONFIG_F2FS_FAULT_INJECTION
  58         if (time_to_inject(F2FS_P_SB(bio->bi_io_vec->bv_page), FAULT_IO))
  59                 bio->bi_error = -EIO;
  60 #endif
  61
  62         if (f2fs_bio_encrypted(bio)) {
  63                 if (bio->bi_error) {
  64                         fscrypt_release_ctx(bio->bi_private);
  65                 } else {
  66                         fscrypt_decrypt_bio_pages(bio->bi_private, bio);
  67                         return;
  68                 }
  69         }
  70
  71         bio_for_each_segment_all(bvec, bio, i) {
  72                 struct page *page = bvec->bv_page;
  73
  74                 if (!bio->bi_error) {
  75                         if (!PageUptodate(page))
  76                                 SetPageUptodate(page);
  77                 } else {
  78                         ClearPageUptodate(page);
  79                         SetPageError(page);
  80                 }
  81                 unlock_page(page);
  82         }
  83         bio_put(bio);
  84 }
  85
  86 static void f2fs_write_end_io(struct bio *bio)
  87 {
  88         struct f2fs_sb_info *sbi = bio->bi_private;
  89         struct bio_vec *bvec;
  90         int i;
  91
  92         bio_for_each_segment_all(bvec, bio, i) {
  93                 struct page *page = bvec->bv_page;
  94                 enum count_type type = WB_DATA_TYPE(page);
  95
  96                 fscrypt_pullback_bio_page(&page, true);
  97
  98                 if (unlikely(bio->bi_error)) {
  99                         mapping_set_error(page->mapping, -EIO);
 100                         f2fs_stop_checkpoint(sbi, true);
 101                 }
 102                 dec_page_count(sbi, type);
 103                 clear_cold_data(page);
 104                 end_page_writeback(page);
 105         }
 106         if (!get_pages(sbi, F2FS_WB_CP_DATA) &&
 107                                 wq_has_sleeper(&sbi->cp_wait))
 108                 wake_up(&sbi->cp_wait);
 109
 110         bio_put(bio);
 111 }
 112
 113 /*
 114  * Return true, if pre_bio's bdev is same as its target device.
 115  */
 116 struct block_device *f2fs_target_device(struct f2fs_sb_info *sbi,
 117                                 block_t blk_addr, struct bio *bio)
 118 {
 119         struct block_device *bdev = sbi->sb->s_bdev;
 120         int i;
 121
 122         for (i = 0; i < sbi->s_ndevs; i++) {
 123                 if (FDEV(i).start_blk <= blk_addr &&
 124                                         FDEV(i).end_blk >= blk_addr) {
 125                         blk_addr -= FDEV(i).start_blk;
 126                         bdev = FDEV(i).bdev;
 127                         break;
 128                 }
 129         }
 130         if (bio) {
 131                 bio->bi_bdev = bdev;
 132                 bio->bi_iter.bi_sector = SECTOR_FROM_BLOCK(blk_addr);
 133         }
 134         return bdev;
 135 }
 136
 137 int f2fs_target_device_index(struct f2fs_sb_info *sbi, block_t blkaddr)
 138 {
 139         int i;
 140
 141         for (i = 0; i < sbi->s_ndevs; i++)
 142                 if (FDEV(i).start_blk <= blkaddr && FDEV(i).end_blk >= blkaddr)
 143                         return i;
 144         return 0;
 145 }
 146
 147 static bool __same_bdev(struct f2fs_sb_info *sbi,
 148                                 block_t blk_addr, struct bio *bio)
 149 {
 150         return f2fs_target_device(sbi, blk_addr, NULL) == bio->bi_bdev;
 151 }
 152
 153 /*
 154  * Low-level block read/write IO operations.
 155  */
 156 static struct bio *__bio_alloc(struct f2fs_sb_info *sbi, block_t blk_addr,
 157                                 int npages, bool is_read)
 158 {
 159         struct bio *bio;
 160
 161         bio = f2fs_bio_alloc(npages);
 162
 163         f2fs_target_device(sbi, blk_addr, bio);
 164         bio->bi_end_io = is_read ? f2fs_read_end_io : f2fs_write_end_io;
 165         bio->bi_private = is_read ? NULL : sbi;
 166
 167         return bio;
 168 }
 169
 170 static inline void __submit_bio(struct f2fs_sb_info *sbi,
 171                                 struct bio *bio, enum page_type type)
 172 {
 173         if (!is_read_io(bio_op(bio))) {
 174                 if (f2fs_sb_mounted_blkzoned(sbi->sb) &&
 175                         current->plug && (type == DATA || type == NODE))
 176                         blk_finish_plug(current->plug);
 177         }
 178         submit_bio(bio);
 179 }
 180
 181 static void __submit_merged_bio(struct f2fs_bio_info *io)
 182 {
 183         struct f2fs_io_info *fio = &io->fio;
 184
 185         if (!io->bio)
 186                 return;
 187
 188         if (is_read_io(fio->op))
 189                 trace_f2fs_submit_read_bio(io->sbi->sb, fio, io->bio);
 190         else
 191                 trace_f2fs_submit_write_bio(io->sbi->sb, fio, io->bio);
 192
 193         bio_set_op_attrs(io->bio, fio->op, fio->op_flags);
 194
 195         __submit_bio(io->sbi, io->bio, fio->type);
 196         io->bio = NULL;
 197 }
 198
 199 static bool __has_merged_page(struct f2fs_bio_info *io, struct inode *inode,
 200                                                 struct page *page, nid_t ino)
 201 {
 202         struct bio_vec *bvec;
 203         struct page *target;
 204         int i;
 205
 206         if (!io->bio)
 207                 return false;
 208
 209         if (!inode && !page && !ino)
 210                 return true;
 211
 212         bio_for_each_segment_all(bvec, io->bio, i) {
 213
 214                 if (bvec->bv_page->mapping)
 215                         target = bvec->bv_page;
 216                 else
 217                         target = fscrypt_control_page(bvec->bv_page);
 218
 219                 if (inode && inode == target->mapping->host)
 220                         return true;
 221                 if (page && page == target)
 222                         return true;
 223                 if (ino && ino == ino_of_node(target))
 224                         return true;
 225         }
 226
 227         return false;
 228 }
 229
 230 static bool has_merged_page(struct f2fs_sb_info *sbi, struct inode *inode,
 231                                                 struct page *page, nid_t ino,
 232                                                 enum page_type type)
 233 {
 234         enum page_type btype = PAGE_TYPE_OF_BIO(type);
 235         struct f2fs_bio_info *io = &sbi->write_io[btype];
 236         bool ret;
 237
 238         down_read(&io->io_rwsem);
 239         ret = __has_merged_page(io, inode, page, ino);
 240         up_read(&io->io_rwsem);
 241         return ret;
 242 }
 243
 244 static void __f2fs_submit_merged_bio(struct f2fs_sb_info *sbi,
 245                                 struct inode *inode, struct page *page,
 246                                 nid_t ino, enum page_type type, int rw)
 247 {
 248         enum page_type btype = PAGE_TYPE_OF_BIO(type);
 249         struct f2fs_bio_info *io;
 250
 251         io = is_read_io(rw) ? &sbi->read_io : &sbi->write_io[btype];
 252
 253         down_write(&io->io_rwsem);
 254
 255         if (!__has_merged_page(io, inode, page, ino))
 256                 goto out;
 257
 258         /* change META to META_FLUSH in the checkpoint procedure */
 259         if (type >= META_FLUSH) {
 260                 io->fio.type = META_FLUSH;
 261                 io->fio.op = REQ_OP_WRITE;
 262                 io->fio.op_flags = REQ_PREFLUSH | REQ_META | REQ_PRIO;
 263                 if (!test_opt(sbi, NOBARRIER))
 264                         io->fio.op_flags |= REQ_FUA;
 265         }
 266         __submit_merged_bio(io);
 267 out:
 268         up_write(&io->io_rwsem);
 269 }
 270
 271 void f2fs_submit_merged_bio(struct f2fs_sb_info *sbi, enum page_type type,
 272                                                                         int rw)
 273 {
 274         __f2fs_submit_merged_bio(sbi, NULL, NULL, 0, type, rw);
 275 }
 276
 277 void f2fs_submit_merged_bio_cond(struct f2fs_sb_info *sbi,
 278                                 struct inode *inode, struct page *page,
 279                                 nid_t ino, enum page_type type, int rw)
 280 {
 281         if (has_merged_page(sbi, inode, page, ino, type))
 282                 __f2fs_submit_merged_bio(sbi, inode, page, ino, type, rw);
 283 }
 284
 285 void f2fs_flush_merged_bios(struct f2fs_sb_info *sbi)
 286 {
 287         f2fs_submit_merged_bio(sbi, DATA, WRITE);
 288         f2fs_submit_merged_bio(sbi, NODE, WRITE);
 289         f2fs_submit_merged_bio(sbi, META, WRITE);
 290 }
 291
 292 /*
 293  * Fill the locked page with data located in the block address.
 294  * Return unlocked page.
 295  */
 296 int f2fs_submit_page_bio(struct f2fs_io_info *fio)
 297 {
 298         struct bio *bio;
 299         struct page *page = fio->encrypted_page ?
 300                         fio->encrypted_page : fio->page;
 301
 302         trace_f2fs_submit_page_bio(page, fio);
 303         f2fs_trace_ios(fio, 0);
 304
 305         /* Allocate a new bio */
 306         bio = __bio_alloc(fio->sbi, fio->new_blkaddr, 1, is_read_io(fio->op));
 307
 308         if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE) {
 309                 bio_put(bio);
 310                 return -EFAULT;
 311         }
 312         bio_set_op_attrs(bio, fio->op, fio->op_flags);
 313
 314         __submit_bio(fio->sbi, bio, fio->type);
 315         return 0;
 316 }
 317
 318 void f2fs_submit_page_mbio(struct f2fs_io_info *fio)
 319 {
 320         struct f2fs_sb_info *sbi = fio->sbi;
 321         enum page_type btype = PAGE_TYPE_OF_BIO(fio->type);
 322         struct f2fs_bio_info *io;
 323         bool is_read = is_read_io(fio->op);
 324         struct page *bio_page;
 325
 326         io = is_read ? &sbi->read_io : &sbi->write_io[btype];
 327
 328         if (fio->old_blkaddr != NEW_ADDR)
 329                 verify_block_addr(sbi, fio->old_blkaddr);
 330         verify_block_addr(sbi, fio->new_blkaddr);
 331
 332         bio_page = fio->encrypted_page ? fio->encrypted_page : fio->page;
 333
 334         if (!is_read)
 335                 inc_page_count(sbi, WB_DATA_TYPE(bio_page));
 336
 337         down_write(&io->io_rwsem);
 338
 339         if (io->bio && (io->last_block_in_bio != fio->new_blkaddr - 1 ||
 340             (io->fio.op != fio->op || io->fio.op_flags != fio->op_flags) ||
 341                         !__same_bdev(sbi, fio->new_blkaddr, io->bio)))
 342                 __submit_merged_bio(io);
 343 alloc_new:
 344         if (io->bio == NULL) {
 345                 io->bio = __bio_alloc(sbi, fio->new_blkaddr,
 346                                                 BIO_MAX_PAGES, is_read);
 347                 io->fio = *fio;
 348         }
 349
 350         if (bio_add_page(io->bio, bio_page, PAGE_SIZE, 0) <
 351                                                         PAGE_SIZE) {
 352                 __submit_merged_bio(io);
 353                 goto alloc_new;
 354         }
 355
 356         io->last_block_in_bio = fio->new_blkaddr;
 357         f2fs_trace_ios(fio, 0);
 358
 359         up_write(&io->io_rwsem);
 360         trace_f2fs_submit_page_mbio(fio->page, fio);
 361 }
 362
 363 static void __set_data_blkaddr(struct dnode_of_data *dn)
 364 {
 365         struct f2fs_node *rn = F2FS_NODE(dn->node_page);
 366         __le32 *addr_array;
 367
 368         /* Get physical address of data block */
 369         addr_array = blkaddr_in_node(rn);
 370         addr_array[dn->ofs_in_node] = cpu_to_le32(dn->data_blkaddr);
 371 }
 372
 373 /*
 374  * Lock ordering for the change of data block address:
 375  * ->data_page
 376  *  ->node_page
 377  *    update block addresses in the node page
 378  */
 379 void set_data_blkaddr(struct dnode_of_data *dn)
 380 {
 381         f2fs_wait_on_page_writeback(dn->node_page, NODE, true);
 382         __set_data_blkaddr(dn);
 383         if (set_page_dirty(dn->node_page))
 384                 dn->node_changed = true;
 385 }
 386
 387 void f2fs_update_data_blkaddr(struct dnode_of_data *dn, block_t blkaddr)
 388 {
 389         dn->data_blkaddr = blkaddr;
 390         set_data_blkaddr(dn);
 391         f2fs_update_extent_cache(dn);
 392 }
 393
 394 /* dn->ofs_in_node will be returned with up-to-date last block pointer */
 395 int reserve_new_blocks(struct dnode_of_data *dn, blkcnt_t count)
 396 {
 397         struct f2fs_sb_info *sbi = F2FS_I_SB(dn->inode);
 398
 399         if (!count)
 400                 return 0;
 401
 402         if (unlikely(is_inode_flag_set(dn->inode, FI_NO_ALLOC)))
 403                 return -EPERM;
 404         if (unlikely(!inc_valid_block_count(sbi, dn->inode, &count)))
 405                 return -ENOSPC;
 406
 407         trace_f2fs_reserve_new_blocks(dn->inode, dn->nid,
 408                                                 dn->ofs_in_node, count);
 409
 410         f2fs_wait_on_page_writeback(dn->node_page, NODE, true);
 411
 412         for (; count > 0; dn->ofs_in_node++) {
 413                 block_t blkaddr =
 414                         datablock_addr(dn->node_page, dn->ofs_in_node);
 415                 if (blkaddr == NULL_ADDR) {
 416                         dn->data_blkaddr = NEW_ADDR;
 417                         __set_data_blkaddr(dn);
 418                         count--;
 419                 }
 420         }
 421
 422         if (set_page_dirty(dn->node_page))
 423                 dn->node_changed = true;
 424         return 0;
 425 }
 426
 427 /* Should keep dn->ofs_in_node unchanged */
 428 int reserve_new_block(struct dnode_of_data *dn)
 429 {
 430         unsigned int ofs_in_node = dn->ofs_in_node;
 431         int ret;
 432
 433         ret = reserve_new_blocks(dn, 1);
 434         dn->ofs_in_node = ofs_in_node;
 435         return ret;
 436 }
 437
 438 int f2fs_reserve_block(struct dnode_of_data *dn, pgoff_t index)
 439 {
 440         bool need_put = dn->inode_page ? false : true;
 441         int err;
 442
 443         err = get_dnode_of_data(dn, index, ALLOC_NODE);
 444         if (err)
 445                 return err;
 446
 447         if (dn->data_blkaddr == NULL_ADDR)
 448                 err = reserve_new_block(dn);
 449         if (err || need_put)
 450                 f2fs_put_dnode(dn);
 451         return err;
 452 }
 453
 454 int f2fs_get_block(struct dnode_of_data *dn, pgoff_t index)
 455 {
 456         struct extent_info ei;
 457         struct inode *inode = dn->inode;
 458
 459         if (f2fs_lookup_extent_cache(inode, index, &ei)) {
 460                 dn->data_blkaddr = ei.blk + index - ei.fofs;
 461                 return 0;
 462         }
 463
 464         return f2fs_reserve_block(dn, index);
 465 }
 466
 467 struct page *get_read_data_page(struct inode *inode, pgoff_t index,
 468                                                 int op_flags, bool for_write)
 469 {
 470         struct address_space *mapping = inode->i_mapping;
 471         struct dnode_of_data dn;
 472         struct page *page;
 473         struct extent_info ei;
 474         int err;
 475         struct f2fs_io_info fio = {
 476                 .sbi = F2FS_I_SB(inode),
 477                 .type = DATA,
 478                 .op = REQ_OP_READ,
 479                 .op_flags = op_flags,
 480                 .encrypted_page = NULL,
 481         };
 482
 483         if (f2fs_encrypted_inode(inode) && S_ISREG(inode->i_mode))
 484                 return read_mapping_page(mapping, index, NULL);
 485
 486         page = f2fs_grab_cache_page(mapping, index, for_write);
 487         if (!page)
 488                 return ERR_PTR(-ENOMEM);
 489
 490         if (f2fs_lookup_extent_cache(inode, index, &ei)) {
 491                 dn.data_blkaddr = ei.blk + index - ei.fofs;
 492                 goto got_it;
 493         }
 494
 495         set_new_dnode(&dn, inode, NULL, NULL, 0);
 496         err = get_dnode_of_data(&dn, index, LOOKUP_NODE);
 497         if (err)
 498                 goto put_err;
 499         f2fs_put_dnode(&dn);
 500
 501         if (unlikely(dn.data_blkaddr == NULL_ADDR)) {
 502                 err = -ENOENT;
 503                 goto put_err;
 504         }
 505 got_it:
 506         if (PageUptodate(page)) {
 507                 unlock_page(page);
 508                 return page;
 509         }
 510
 511         /*
 512          * A new dentry page is allocated but not able to be written, since its
 513          * new inode page couldn't be allocated due to -ENOSPC.
 514          * In such the case, its blkaddr can be remained as NEW_ADDR.
 515          * see, f2fs_add_link -> get_new_data_page -> init_inode_metadata.
 516          */
 517         if (dn.data_blkaddr == NEW_ADDR) {
 518                 zero_user_segment(page, 0, PAGE_SIZE);
 519                 if (!PageUptodate(page))
 520                         SetPageUptodate(page);
 521                 unlock_page(page);
 522                 return page;
 523         }
 524
 525         fio.new_blkaddr = fio.old_blkaddr = dn.data_blkaddr;
 526         fio.page = page;
 527         err = f2fs_submit_page_bio(&fio);
 528         if (err)
 529                 goto put_err;
 530         return page;
 531
 532 put_err:
 533         f2fs_put_page(page, 1);
 534         return ERR_PTR(err);
 535 }
 536
 537 struct page *find_data_page(struct inode *inode, pgoff_t index)
 538 {
 539         struct address_space *mapping = inode->i_mapping;
 540         struct page *page;
 541
 542         page = find_get_page(mapping, index);
 543         if (page && PageUptodate(page))
 544                 return page;
 545         f2fs_put_page(page, 0);
 546
 547         page = get_read_data_page(inode, index, 0, false);
 548         if (IS_ERR(page))
 549                 return page;
 550
 551         if (PageUptodate(page))
 552                 return page;
 553
 554         wait_on_page_locked(page);
 555         if (unlikely(!PageUptodate(page))) {
 556                 f2fs_put_page(page, 0);
 557                 return ERR_PTR(-EIO);
 558         }
 559         return page;
 560 }
 561
 562 /*
 563  * If it tries to access a hole, return an error.
 564  * Because, the callers, functions in dir.c and GC, should be able to know
 565  * whether this page exists or not.
 566  */
 567 struct page *get_lock_data_page(struct inode *inode, pgoff_t index,
 568                                                         bool for_write)
 569 {
 570         struct address_space *mapping = inode->i_mapping;
 571         struct page *page;
 572 repeat:
 573         page = get_read_data_page(inode, index, 0, for_write);
 574         if (IS_ERR(page))
 575                 return page;
 576
 577         /* wait for read completion */
 578         lock_page(page);
 579         if (unlikely(page->mapping != mapping)) {
 580                 f2fs_put_page(page, 1);
 581                 goto repeat;
 582         }
 583         if (unlikely(!PageUptodate(page))) {
 584                 f2fs_put_page(page, 1);
 585                 return ERR_PTR(-EIO);
 586         }
 587         return page;
 588 }
 589
 590 /*
 591  * Caller ensures that this data page is never allocated.
 592  * A new zero-filled data page is allocated in the page cache.
 593  *
 594  * Also, caller should grab and release a rwsem by calling f2fs_lock_op() and
 595  * f2fs_unlock_op().
 596  * Note that, ipage is set only by make_empty_dir, and if any error occur,
 597  * ipage should be released by this function.
 598  */
 599 struct page *get_new_data_page(struct inode *inode,
 600                 struct page *ipage, pgoff_t index, bool new_i_size)
 601 {
 602         struct address_space *mapping = inode->i_mapping;
 603         struct page *page;
 604         struct dnode_of_data dn;
 605         int err;
 606
 607         page = f2fs_grab_cache_page(mapping, index, true);
 608         if (!page) {
 609                 /*
 610                  * before exiting, we should make sure ipage will be released
 611                  * if any error occur.
 612                  */
 613                 f2fs_put_page(ipage, 1);
 614                 return ERR_PTR(-ENOMEM);
 615         }
 616
 617         set_new_dnode(&dn, inode, ipage, NULL, 0);
 618         err = f2fs_reserve_block(&dn, index);
 619         if (err) {
 620                 f2fs_put_page(page, 1);
 621                 return ERR_PTR(err);
 622         }
 623         if (!ipage)
 624                 f2fs_put_dnode(&dn);
 625
 626         if (PageUptodate(page))
 627                 goto got_it;
 628
 629         if (dn.data_blkaddr == NEW_ADDR) {
 630                 zero_user_segment(page, 0, PAGE_SIZE);
 631                 if (!PageUptodate(page))
 632                         SetPageUptodate(page);
 633         } else {
 634                 f2fs_put_page(page, 1);
 635
 636                 /* if ipage exists, blkaddr should be NEW_ADDR */
 637                 f2fs_bug_on(F2FS_I_SB(inode), ipage);
 638                 page = get_lock_data_page(inode, index, true);
 639                 if (IS_ERR(page))
 640                         return page;
 641         }
 642 got_it:
 643         if (new_i_size && i_size_read(inode) <
 644                                 ((loff_t)(index + 1) << PAGE_SHIFT))
 645                 f2fs_i_size_write(inode, ((loff_t)(index + 1) << PAGE_SHIFT));
 646         return page;
 647 }
 648
 649 static int __allocate_data_block(struct dnode_of_data *dn)
 650 {
 651         struct f2fs_sb_info *sbi = F2FS_I_SB(dn->inode);
 652         struct f2fs_summary sum;
 653         struct node_info ni;
 654         pgoff_t fofs;
 655         blkcnt_t count = 1;
 656
 657         if (unlikely(is_inode_flag_set(dn->inode, FI_NO_ALLOC)))
 658                 return -EPERM;
 659
 660         dn->data_blkaddr = datablock_addr(dn->node_page, dn->ofs_in_node);
 661         if (dn->data_blkaddr == NEW_ADDR)
 662                 goto alloc;
 663
 664         if (unlikely(!inc_valid_block_count(sbi, dn->inode, &count)))
 665                 return -ENOSPC;
 666
 667 alloc:
 668         get_node_info(sbi, dn->nid, &ni);
 669         set_summary(&sum, dn->nid, dn->ofs_in_node, ni.version);
 670
 671         allocate_data_block(sbi, NULL, dn->data_blkaddr, &dn->data_blkaddr,
 672                                                 &sum, CURSEG_WARM_DATA);
 673         set_data_blkaddr(dn);
 674
 675         /* update i_size */
 676         fofs = start_bidx_of_node(ofs_of_node(dn->node_page), dn->inode) +
 677                                                         dn->ofs_in_node;
 678         if (i_size_read(dn->inode) < ((loff_t)(fofs + 1) << PAGE_SHIFT))
 679                 f2fs_i_size_write(dn->inode,
 680                                 ((loff_t)(fofs + 1) << PAGE_SHIFT));
 681         return 0;
 682 }
 683
 684 static inline bool __force_buffered_io(struct inode *inode, int rw)
 685 {
 686         return ((f2fs_encrypted_inode(inode) && S_ISREG(inode->i_mode)) ||
 687                         (rw == WRITE && test_opt(F2FS_I_SB(inode), LFS)) ||
 688                         F2FS_I_SB(inode)->s_ndevs);
 689 }
 690
 691 int f2fs_preallocate_blocks(struct kiocb *iocb, struct iov_iter *from)
 692 {
 693         struct inode *inode = file_inode(iocb->ki_filp);
 694         struct f2fs_map_blocks map;
 695         int err = 0;
 696
 697         map.m_lblk = F2FS_BLK_ALIGN(iocb->ki_pos);
 698         map.m_len = F2FS_BYTES_TO_BLK(iocb->ki_pos + iov_iter_count(from));
 699         if (map.m_len > map.m_lblk)
 700                 map.m_len -= map.m_lblk;
 701         else
 702                 map.m_len = 0;
 703
 704         map.m_next_pgofs = NULL;
 705
 706         if (iocb->ki_flags & IOCB_DIRECT) {
 707                 err = f2fs_convert_inline_inode(inode);
 708                 if (err)
 709                         return err;
 710                 return f2fs_map_blocks(inode, &map, 1,
 711                         __force_buffered_io(inode, WRITE) ?
 712                                 F2FS_GET_BLOCK_PRE_AIO :
 713                                 F2FS_GET_BLOCK_PRE_DIO);
 714         }
 715         if (iocb->ki_pos + iov_iter_count(from) > MAX_INLINE_DATA) {
 716                 err = f2fs_convert_inline_inode(inode);
 717                 if (err)
 718                         return err;
 719         }
 720         if (!f2fs_has_inline_data(inode))
 721                 return f2fs_map_blocks(inode, &map, 1, F2FS_GET_BLOCK_PRE_AIO);
 722         return err;
 723 }
 724
 725 /*
 726  * f2fs_map_blocks() now supported readahead/bmap/rw direct_IO with
 727  * f2fs_map_blocks structure.
 728  * If original data blocks are allocated, then give them to blockdev.
 729  * Otherwise,
 730  *     a. preallocate requested block addresses
 731  *     b. do not use extent cache for better performance
 732  *     c. give the block addresses to blockdev
 733  */
 734 int f2fs_map_blocks(struct inode *inode, struct f2fs_map_blocks *map,
 735                                                 int create, int flag)
 736 {
 737         unsigned int maxblocks = map->m_len;
 738         struct dnode_of_data dn;
 739         struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
 740         int mode = create ? ALLOC_NODE : LOOKUP_NODE;
 741         pgoff_t pgofs, end_offset, end;
 742         int err = 0, ofs = 1;
 743         unsigned int ofs_in_node, last_ofs_in_node;
 744         blkcnt_t prealloc;
 745         struct extent_info ei;
 746         block_t blkaddr;
 747
 748         if (!maxblocks)
 749                 return 0;
 750
 751         map->m_len = 0;
 752         map->m_flags = 0;
 753
 754         /* it only supports block size == page size */
 755         pgofs = (pgoff_t)map->m_lblk;
 756         end = pgofs + maxblocks;
 757
 758         if (!create && f2fs_lookup_extent_cache(inode, pgofs, &ei)) {
 759                 map->m_pblk = ei.blk + pgofs - ei.fofs;
 760                 map->m_len = min((pgoff_t)maxblocks, ei.fofs + ei.len - pgofs);
 761                 map->m_flags = F2FS_MAP_MAPPED;
 762                 goto out;
 763         }
 764
 765 next_dnode:
 766         if (create)
 767                 f2fs_lock_op(sbi);
 768
 769         /* When reading holes, we need its node page */
 770         set_new_dnode(&dn, inode, NULL, NULL, 0);
 771         err = get_dnode_of_data(&dn, pgofs, mode);
 772         if (err) {
 773                 if (flag == F2FS_GET_BLOCK_BMAP)
 774                         map->m_pblk = 0;
 775                 if (err == -ENOENT) {
 776                         err = 0;
 777                         if (map->m_next_pgofs)
 778                                 *map->m_next_pgofs =
 779                                         get_next_page_offset(&dn, pgofs);
 780                 }
 781                 goto unlock_out;
 782         }
 783
 784         prealloc = 0;
 785         last_ofs_in_node = ofs_in_node = dn.ofs_in_node;
 786         end_offset = ADDRS_PER_PAGE(dn.node_page, inode);
 787
 788 next_block:
 789         blkaddr = datablock_addr(dn.node_page, dn.ofs_in_node);
 790
 791         if (blkaddr == NEW_ADDR || blkaddr == NULL_ADDR) {
 792                 if (create) {
 793                         if (unlikely(f2fs_cp_error(sbi))) {
 794                                 err = -EIO;
 795                                 goto sync_out;
 796                         }
 797                         if (flag == F2FS_GET_BLOCK_PRE_AIO) {
 798                                 if (blkaddr == NULL_ADDR) {
 799                                         prealloc++;
 800                                         last_ofs_in_node = dn.ofs_in_node;
 801                                 }
 802                         } else {
 803                                 err = __allocate_data_block(&dn);
 804                                 if (!err)
 805                                         set_inode_flag(inode, FI_APPEND_WRITE);
 806                         }
 807                         if (err)
 808                                 goto sync_out;
 809                         map->m_flags = F2FS_MAP_NEW;
 810                         blkaddr = dn.data_blkaddr;
 811                 } else {
 812                         if (flag == F2FS_GET_BLOCK_BMAP) {
 813                                 map->m_pblk = 0;
 814                                 goto sync_out;
 815                         }
 816                         if (flag == F2FS_GET_BLOCK_FIEMAP &&
 817                                                 blkaddr == NULL_ADDR) {
 818                                 if (map->m_next_pgofs)
 819                                         *map->m_next_pgofs = pgofs + 1;
 820                         }
 821                         if (flag != F2FS_GET_BLOCK_FIEMAP ||
 822                                                 blkaddr != NEW_ADDR)
 823                                 goto sync_out;
 824                 }
 825         }
 826
 827         if (flag == F2FS_GET_BLOCK_PRE_AIO)
 828                 goto skip;
 829
 830         if (map->m_len == 0) {
 831                 /* preallocated unwritten block should be mapped for fiemap. */
 832                 if (blkaddr == NEW_ADDR)
 833                         map->m_flags |= F2FS_MAP_UNWRITTEN;
 834                 map->m_flags |= F2FS_MAP_MAPPED;
 835
 836                 map->m_pblk = blkaddr;
 837                 map->m_len = 1;
 838         } else if ((map->m_pblk != NEW_ADDR &&
 839                         blkaddr == (map->m_pblk + ofs)) ||
 840                         (map->m_pblk == NEW_ADDR && blkaddr == NEW_ADDR) ||
 841                         flag == F2FS_GET_BLOCK_PRE_DIO) {
 842                 ofs++;
 843                 map->m_len++;
 844         } else {
 845                 goto sync_out;
 846         }
 847
 848 skip:
 849         dn.ofs_in_node++;
 850         pgofs++;
 851
 852         /* preallocate blocks in batch for one dnode page */
 853         if (flag == F2FS_GET_BLOCK_PRE_AIO &&
 854                         (pgofs == end || dn.ofs_in_node == end_offset)) {
 855
 856                 dn.ofs_in_node = ofs_in_node;
 857                 err = reserve_new_blocks(&dn, prealloc);
 858                 if (err)
 859                         goto sync_out;
 860
 861                 map->m_len += dn.ofs_in_node - ofs_in_node;
 862                 if (prealloc && dn.ofs_in_node != last_ofs_in_node + 1) {
 863                         err = -ENOSPC;
 864                         goto sync_out;
 865                 }
 866                 dn.ofs_in_node = end_offset;
 867         }
 868
 869         if (pgofs >= end)
 870                 goto sync_out;
 871         else if (dn.ofs_in_node < end_offset)
 872                 goto next_block;
 873
 874         f2fs_put_dnode(&dn);
 875
 876         if (create) {
 877                 f2fs_unlock_op(sbi);
 878                 f2fs_balance_fs(sbi, dn.node_changed);
 879         }
 880         goto next_dnode;
 881
 882 sync_out:
 883         f2fs_put_dnode(&dn);
 884 unlock_out:
 885         if (create) {
 886                 f2fs_unlock_op(sbi);
 887                 f2fs_balance_fs(sbi, dn.node_changed);
 888         }
 889 out:
 890         trace_f2fs_map_blocks(inode, map, err);
 891         return err;
 892 }
 893
 894 static int __get_data_block(struct inode *inode, sector_t iblock,
 895                         struct buffer_head *bh, int create, int flag,
 896                         pgoff_t *next_pgofs)
 897 {
 898         struct f2fs_map_blocks map;
 899         int err;
 900
 901         map.m_lblk = iblock;
 902         map.m_len = bh->b_size >> inode->i_blkbits;
 903         map.m_next_pgofs = next_pgofs;
 904
 905         err = f2fs_map_blocks(inode, &map, create, flag);
 906         if (!err) {
 907                 map_bh(bh, inode->i_sb, map.m_pblk);
 908                 bh->b_state = (bh->b_state & ~F2FS_MAP_FLAGS) | map.m_flags;
 909                 bh->b_size = map.m_len << inode->i_blkbits;
 910         }
 911         return err;
 912 }
 913
 914 static int get_data_block(struct inode *inode, sector_t iblock,
 915                         struct buffer_head *bh_result, int create, int flag,
 916                         pgoff_t *next_pgofs)
 917 {
 918         return __get_data_block(inode, iblock, bh_result, create,
 919                                                         flag, next_pgofs);
 920 }
 921
 922 static int get_data_block_dio(struct inode *inode, sector_t iblock,
 923                         struct buffer_head *bh_result, int create)
 924 {
 925         return __get_data_block(inode, iblock, bh_result, create,
 926                                                 F2FS_GET_BLOCK_DIO, NULL);
 927 }
 928
 929 static int get_data_block_bmap(struct inode *inode, sector_t iblock,
 930                         struct buffer_head *bh_result, int create)
 931 {
 932         /* Block number less than F2FS MAX BLOCKS */
 933         if (unlikely(iblock >= F2FS_I_SB(inode)->max_file_blocks))
 934                 return -EFBIG;
 935
 936         return __get_data_block(inode, iblock, bh_result, create,
 937                                                 F2FS_GET_BLOCK_BMAP, NULL);
 938 }
 939
 940 static inline sector_t logical_to_blk(struct inode *inode, loff_t offset)
 941 {
 942         return (offset >> inode->i_blkbits);
 943 }
 944
 945 static inline loff_t blk_to_logical(struct inode *inode, sector_t blk)
 946 {
 947         return (blk << inode->i_blkbits);
 948 }
 949
 950 int f2fs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
 951                 u64 start, u64 len)
 952 {
 953         struct buffer_head map_bh;
 954         sector_t start_blk, last_blk;
 955         pgoff_t next_pgofs;
 956         u64 logical = 0, phys = 0, size = 0;
 957         u32 flags = 0;
 958         int ret = 0;
 959
 960         ret = fiemap_check_flags(fieinfo, FIEMAP_FLAG_SYNC);
 961         if (ret)
 962                 return ret;
 963
 964         if (f2fs_has_inline_data(inode)) {
 965                 ret = f2fs_inline_data_fiemap(inode, fieinfo, start, len);
 966                 if (ret != -EAGAIN)
 967                         return ret;
 968         }
 969
 970         inode_lock(inode);
 971
 972         if (logical_to_blk(inode, len) == 0)
 973                 len = blk_to_logical(inode, 1);
 974
 975         start_blk = logical_to_blk(inode, start);
 976         last_blk = logical_to_blk(inode, start + len - 1);
 977
 978 next:
 979         memset(&map_bh, 0, sizeof(struct buffer_head));
 980         map_bh.b_size = len;
 981
 982         ret = get_data_block(inode, start_blk, &map_bh, 0,
 983                                         F2FS_GET_BLOCK_FIEMAP, &next_pgofs);
 984         if (ret)
 985                 goto out;
 986
 987         /* HOLE */
 988         if (!buffer_mapped(&map_bh)) {
 989                 start_blk = next_pgofs;
 990
 991                 if (blk_to_logical(inode, start_blk) < blk_to_logical(inode,
 992                                         F2FS_I_SB(inode)->max_file_blocks))
 993                         goto prep_next;
 994
 995                 flags |= FIEMAP_EXTENT_LAST;
 996         }
 997
 998         if (size) {
 999                 if (f2fs_encrypted_inode(inode))
1000                         flags |= FIEMAP_EXTENT_DATA_ENCRYPTED;
1001
1002                 ret = fiemap_fill_next_extent(fieinfo, logical,
1003                                 phys, size, flags);
1004         }
1005
1006         if (start_blk > last_blk || ret)
1007                 goto out;
1008
1009         logical = blk_to_logical(inode, start_blk);
1010         phys = blk_to_logical(inode, map_bh.b_blocknr);
1011         size = map_bh.b_size;
1012         flags = 0;
1013         if (buffer_unwritten(&map_bh))
1014                 flags = FIEMAP_EXTENT_UNWRITTEN;
1015
1016         start_blk += logical_to_blk(inode, size);
1017
1018 prep_next:
1019         cond_resched();
1020         if (fatal_signal_pending(current))
1021                 ret = -EINTR;
1022         else
1023                 goto next;
1024 out:
1025         if (ret == 1)
1026                 ret = 0;
1027
1028         inode_unlock(inode);
1029         return ret;
1030 }
1031
1032 static struct bio *f2fs_grab_bio(struct inode *inode, block_t blkaddr,
1033                                  unsigned nr_pages)
1034 {
1035         struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
1036         struct fscrypt_ctx *ctx = NULL;
1037         struct bio *bio;
1038
1039         if (f2fs_encrypted_inode(inode) && S_ISREG(inode->i_mode)) {
1040                 ctx = fscrypt_get_ctx(inode, GFP_NOFS);
1041                 if (IS_ERR(ctx))
1042                         return ERR_CAST(ctx);
1043
1044                 /* wait the page to be moved by cleaning */
1045                 f2fs_wait_on_encrypted_page_writeback(sbi, blkaddr);
1046         }
1047
1048         bio = bio_alloc(GFP_KERNEL, min_t(int, nr_pages, BIO_MAX_PAGES));
1049         if (!bio) {
1050                 if (ctx)
1051                         fscrypt_release_ctx(ctx);
1052                 return ERR_PTR(-ENOMEM);
1053         }
1054         f2fs_target_device(sbi, blkaddr, bio);
1055         bio->bi_end_io = f2fs_read_end_io;
1056         bio->bi_private = ctx;
1057
1058         return bio;
1059 }
1060
1061 /*
1062  * This function was originally taken from fs/mpage.c, and customized for f2fs.
1063  * Major change was from block_size == page_size in f2fs by default.
1064  */
1065 static int f2fs_mpage_readpages(struct address_space *mapping,
1066                         struct list_head *pages, struct page *page,
1067                         unsigned nr_pages)
1068 {
1069         struct bio *bio = NULL;
1070         unsigned page_idx;
1071         sector_t last_block_in_bio = 0;
1072         struct inode *inode = mapping->host;
1073         const unsigned blkbits = inode->i_blkbits;
1074         const unsigned blocksize = 1 << blkbits;
1075         sector_t block_in_file;
1076         sector_t last_block;
1077         sector_t last_block_in_file;
1078         sector_t block_nr;
1079         struct f2fs_map_blocks map;
1080
1081         map.m_pblk = 0;
1082         map.m_lblk = 0;
1083         map.m_len = 0;
1084         map.m_flags = 0;
1085         map.m_next_pgofs = NULL;
1086
1087         for (page_idx = 0; nr_pages; page_idx++, nr_pages--) {
1088
1089                 prefetchw(&page->flags);
1090                 if (pages) {
1091                         page = list_entry(pages->prev, struct page, lru);
1092                         list_del(&page->lru);
1093                         if (add_to_page_cache_lru(page, mapping,
1094                                                   page->index,
1095                                                   readahead_gfp_mask(mapping)))
1096                                 goto next_page;
1097                 }
1098
1099                 block_in_file = (sector_t)page->index;
1100                 last_block = block_in_file + nr_pages;
1101                 last_block_in_file = (i_size_read(inode) + blocksize - 1) >>
1102                                                                 blkbits;
1103                 if (last_block > last_block_in_file)
1104                         last_block = last_block_in_file;
1105
1106                 /*
1107                  * Map blocks using the previous result first.
1108                  */
1109                 if ((map.m_flags & F2FS_MAP_MAPPED) &&
1110                                 block_in_file > map.m_lblk &&
1111                                 block_in_file < (map.m_lblk + map.m_len))
1112                         goto got_it;
1113
1114                 /*
1115                  * Then do more f2fs_map_blocks() calls until we are
1116                  * done with this page.
1117                  */
1118                 map.m_flags = 0;
1119
1120                 if (block_in_file < last_block) {
1121                         map.m_lblk = block_in_file;
1122                         map.m_len = last_block - block_in_file;
1123
1124                         if (f2fs_map_blocks(inode, &map, 0,
1125                                                 F2FS_GET_BLOCK_READ))
1126                                 goto set_error_page;
1127                 }
1128 got_it:
1129                 if ((map.m_flags & F2FS_MAP_MAPPED)) {
1130                         block_nr = map.m_pblk + block_in_file - map.m_lblk;
1131                         SetPageMappedToDisk(page);
1132
1133                         if (!PageUptodate(page) && !cleancache_get_page(page)) {
1134                                 SetPageUptodate(page);
1135                                 goto confused;
1136                         }
1137                 } else {
1138                         zero_user_segment(page, 0, PAGE_SIZE);
1139                         if (!PageUptodate(page))
1140                                 SetPageUptodate(page);
1141                         unlock_page(page);
1142                         goto next_page;
1143                 }
1144
1145                 /*
1146                  * This page will go to BIO.  Do we need to send this
1147                  * BIO off first?
1148                  */
1149                 if (bio && (last_block_in_bio != block_nr - 1 ||
1150                         !__same_bdev(F2FS_I_SB(inode), block_nr, bio))) {
1151 submit_and_realloc:
1152                         __submit_bio(F2FS_I_SB(inode), bio, DATA);
1153                         bio = NULL;
1154                 }
1155                 if (bio == NULL) {
1156                         bio = f2fs_grab_bio(inode, block_nr, nr_pages);
1157                         if (IS_ERR(bio)) {
1158                                 bio = NULL;
1159                                 goto set_error_page;
1160                         }
1161                         bio_set_op_attrs(bio, REQ_OP_READ, 0);
1162                 }
1163
1164                 if (bio_add_page(bio, page, blocksize, 0) < blocksize)
1165                         goto submit_and_realloc;
1166
1167                 last_block_in_bio = block_nr;
1168                 goto next_page;
1169 set_error_page:
1170                 SetPageError(page);
1171                 zero_user_segment(page, 0, PAGE_SIZE);
1172                 unlock_page(page);
1173                 goto next_page;
1174 confused:
1175                 if (bio) {
1176                         __submit_bio(F2FS_I_SB(inode), bio, DATA);
1177                         bio = NULL;
1178                 }
1179                 unlock_page(page);
1180 next_page:
1181                 if (pages)
1182                         put_page(page);
1183         }
1184         BUG_ON(pages && !list_empty(pages));
1185         if (bio)
1186                 __submit_bio(F2FS_I_SB(inode), bio, DATA);
1187         return 0;
1188 }
1189
1190 static int f2fs_read_data_page(struct file *file, struct page *page)
1191 {
1192         struct inode *inode = page->mapping->host;
1193         int ret = -EAGAIN;
1194
1195         trace_f2fs_readpage(page, DATA);
1196
1197         /* If the file has inline data, try to read it directly */
1198         if (f2fs_has_inline_data(inode))
1199                 ret = f2fs_read_inline_data(inode, page);
1200         if (ret == -EAGAIN)
1201                 ret = f2fs_mpage_readpages(page->mapping, NULL, page, 1);
1202         return ret;
1203 }
1204
1205 static int f2fs_read_data_pages(struct file *file,
1206                         struct address_space *mapping,
1207                         struct list_head *pages, unsigned nr_pages)
1208 {
1209         struct inode *inode = file->f_mapping->host;
1210         struct page *page = list_entry(pages->prev, struct page, lru);
1211
1212         trace_f2fs_readpages(inode, page, nr_pages);
1213
1214         /* If the file has inline data, skip readpages */
1215         if (f2fs_has_inline_data(inode))
1216                 return 0;
1217
1218         return f2fs_mpage_readpages(mapping, pages, NULL, nr_pages);
1219 }
1220
1221 int do_write_data_page(struct f2fs_io_info *fio)
1222 {
1223         struct page *page = fio->page;
1224         struct inode *inode = page->mapping->host;
1225         struct dnode_of_data dn;
1226         int err = 0;
1227
1228         set_new_dnode(&dn, inode, NULL, NULL, 0);
1229         err = get_dnode_of_data(&dn, page->index, LOOKUP_NODE);
1230         if (err)
1231                 return err;
1232
1233         fio->old_blkaddr = dn.data_blkaddr;
1234
1235         /* This page is already truncated */
1236         if (fio->old_blkaddr == NULL_ADDR) {
1237                 ClearPageUptodate(page);
1238                 goto out_writepage;
1239         }
1240
1241         if (f2fs_encrypted_inode(inode) && S_ISREG(inode->i_mode)) {
1242                 gfp_t gfp_flags = GFP_NOFS;
1243
1244                 /* wait for GCed encrypted page writeback */
1245                 f2fs_wait_on_encrypted_page_writeback(F2FS_I_SB(inode),
1246                                                         fio->old_blkaddr);
1247 retry_encrypt:
1248                 fio->encrypted_page = fscrypt_encrypt_page(inode, fio->page,
1249                                                         PAGE_SIZE, 0,
1250                                                         fio->page->index,
1251                                                         gfp_flags);
1252                 if (IS_ERR(fio->encrypted_page)) {
1253                         err = PTR_ERR(fio->encrypted_page);
1254                         if (err == -ENOMEM) {
1255                                 /* flush pending ios and wait for a while */
1256                                 f2fs_flush_merged_bios(F2FS_I_SB(inode));
1257                                 congestion_wait(BLK_RW_ASYNC, HZ/50);
1258                                 gfp_flags |= __GFP_NOFAIL;
1259                                 err = 0;
1260                                 goto retry_encrypt;
1261                         }
1262                         goto out_writepage;
1263                 }
1264         }
1265
1266         set_page_writeback(page);
1267
1268         /*
1269          * If current allocation needs SSR,
1270          * it had better in-place writes for updated data.
1271          */
1272         if (unlikely(fio->old_blkaddr != NEW_ADDR &&
1273                         !is_cold_data(page) &&
1274                         !IS_ATOMIC_WRITTEN_PAGE(page) &&
1275                         need_inplace_update(inode))) {
1276                 rewrite_data_page(fio);
1277                 set_inode_flag(inode, FI_UPDATE_WRITE);
1278                 trace_f2fs_do_write_data_page(page, IPU);
1279         } else {
1280                 write_data_page(&dn, fio);
1281                 trace_f2fs_do_write_data_page(page, OPU);
1282                 set_inode_flag(inode, FI_APPEND_WRITE);
1283                 if (page->index == 0)
1284                         set_inode_flag(inode, FI_FIRST_BLOCK_WRITTEN);
1285         }
1286 out_writepage:
1287         f2fs_put_dnode(&dn);
1288         return err;
1289 }
1290
1291 static int f2fs_write_data_page(struct page *page,
1292                                         struct writeback_control *wbc)
1293 {
1294         struct inode *inode = page->mapping->host;
1295         struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
1296         loff_t i_size = i_size_read(inode);
1297         const pgoff_t end_index = ((unsigned long long) i_size)
1298                                                         >> PAGE_SHIFT;
1299         loff_t psize = (page->index + 1) << PAGE_SHIFT;
1300         unsigned offset = 0;
1301         bool need_balance_fs = false;
1302         int err = 0;
1303         struct f2fs_io_info fio = {
1304                 .sbi = sbi,
1305                 .type = DATA,
1306                 .op = REQ_OP_WRITE,
1307                 .op_flags = wbc_to_write_flags(wbc),
1308                 .page = page,
1309                 .encrypted_page = NULL,
1310         };
1311
1312         trace_f2fs_writepage(page, DATA);
1313
1314         if (page->index < end_index)
1315                 goto write;
1316
1317         /*
1318          * If the offset is out-of-range of file size,
1319          * this page does not have to be written to disk.
1320          */
1321         offset = i_size & (PAGE_SIZE - 1);
1322         if ((page->index >= end_index + 1) || !offset)
1323                 goto out;
1324
1325         zero_user_segment(page, offset, PAGE_SIZE);
1326 write:
1327         if (unlikely(is_sbi_flag_set(sbi, SBI_POR_DOING)))
1328                 goto redirty_out;
1329         if (f2fs_is_drop_cache(inode))
1330                 goto out;
1331         /* we should not write 0'th page having journal header */
1332         if (f2fs_is_volatile_file(inode) && (!page->index ||
1333                         (!wbc->for_reclaim &&
1334                         available_free_memory(sbi, BASE_CHECK))))
1335                 goto redirty_out;
1336
1337         /* we should bypass data pages to proceed the kworkder jobs */
1338         if (unlikely(f2fs_cp_error(sbi))) {
1339                 mapping_set_error(page->mapping, -EIO);
1340                 goto out;
1341         }
1342
1343         /* Dentry blocks are controlled by checkpoint */
1344         if (S_ISDIR(inode->i_mode)) {
1345                 err = do_write_data_page(&fio);
1346                 goto done;
1347         }
1348
1349         if (!wbc->for_reclaim)
1350                 need_balance_fs = true;
1351         else if (has_not_enough_free_secs(sbi, 0, 0))
1352                 goto redirty_out;
1353
1354         err = -EAGAIN;
1355         f2fs_lock_op(sbi);
1356         if (f2fs_has_inline_data(inode))
1357                 err = f2fs_write_inline_data(inode, page);
1358         if (err == -EAGAIN)
1359                 err = do_write_data_page(&fio);
1360         if (F2FS_I(inode)->last_disk_size < psize)
1361                 F2FS_I(inode)->last_disk_size = psize;
1362         f2fs_unlock_op(sbi);
1363 done:
1364         if (err && err != -ENOENT)
1365                 goto redirty_out;
1366
1367 out:
1368         inode_dec_dirty_pages(inode);
1369         if (err)
1370                 ClearPageUptodate(page);
1371
1372         if (wbc->for_reclaim) {
1373                 f2fs_submit_merged_bio_cond(sbi, NULL, page, 0, DATA, WRITE);
1374                 remove_dirty_inode(inode);
1375         }
1376
1377         unlock_page(page);
1378         f2fs_balance_fs(sbi, need_balance_fs);
1379
1380         if (unlikely(f2fs_cp_error(sbi)))
1381                 f2fs_submit_merged_bio(sbi, DATA, WRITE);
1382
1383         return 0;
1384
1385 redirty_out:
1386         redirty_page_for_writepage(wbc, page);
1387         if (!err)
1388                 return AOP_WRITEPAGE_ACTIVATE;
1389         unlock_page(page);
1390         return err;
1391 }
1392
1393 /*
1394  * This function was copied from write_cche_pages from mm/page-writeback.c.
1395  * The major change is making write step of cold data page separately from
1396  * warm/hot data page.
1397  */
1398 static int f2fs_write_cache_pages(struct address_space *mapping,
1399                                         struct writeback_control *wbc)
1400 {
1401         int ret = 0;
1402         int done = 0;
1403         struct pagevec pvec;
1404         int nr_pages;
1405         pgoff_t uninitialized_var(writeback_index);
1406         pgoff_t index;
1407         pgoff_t end;            /* Inclusive */
1408         pgoff_t done_index;
1409         int cycled;
1410         int range_whole = 0;
1411         int tag;
1412         int nwritten = 0;
1413
1414         pagevec_init(&pvec, 0);
1415
1416         if (wbc->range_cyclic) {
1417                 writeback_index = mapping->writeback_index; /* prev offset */
1418                 index = writeback_index;
1419                 if (index == 0)
1420                         cycled = 1;
1421                 else
1422                         cycled = 0;
1423                 end = -1;
1424         } else {
1425                 index = wbc->range_start >> PAGE_SHIFT;
1426                 end = wbc->range_end >> PAGE_SHIFT;
1427                 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
1428                         range_whole = 1;
1429                 cycled = 1; /* ignore range_cyclic tests */
1430         }
1431         if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)
1432                 tag = PAGECACHE_TAG_TOWRITE;
1433         else
1434                 tag = PAGECACHE_TAG_DIRTY;
1435 retry:
1436         if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)
1437                 tag_pages_for_writeback(mapping, index, end);
1438         done_index = index;
1439         while (!done && (index <= end)) {
1440                 int i;
1441
1442                 nr_pages = pagevec_lookup_tag(&pvec, mapping, &index, tag,
1443                               min(end - index, (pgoff_t)PAGEVEC_SIZE - 1) + 1);
1444                 if (nr_pages == 0)
1445                         break;
1446
1447                 for (i = 0; i < nr_pages; i++) {
1448                         struct page *page = pvec.pages[i];
1449
1450                         if (page->index > end) {
1451                                 done = 1;
1452                                 break;
1453                         }
1454
1455                         done_index = page->index;
1456
1457                         lock_page(page);
1458
1459                         if (unlikely(page->mapping != mapping)) {
1460 continue_unlock:
1461                                 unlock_page(page);
1462                                 continue;
1463                         }
1464
1465                         if (!PageDirty(page)) {
1466                                 /* someone wrote it for us */
1467                                 goto continue_unlock;
1468                         }
1469
1470                         if (PageWriteback(page)) {
1471                                 if (wbc->sync_mode != WB_SYNC_NONE)
1472                                         f2fs_wait_on_page_writeback(page,
1473                                                                 DATA, true);
1474                                 else
1475                                         goto continue_unlock;
1476                         }
1477
1478                         BUG_ON(PageWriteback(page));
1479                         if (!clear_page_dirty_for_io(page))
1480                                 goto continue_unlock;
1481
1482                         ret = mapping->a_ops->writepage(page, wbc);
1483                         if (unlikely(ret)) {
1484                                 /*
1485                                  * keep nr_to_write, since vfs uses this to
1486                                  * get # of written pages.
1487                                  */
1488                                 if (ret == AOP_WRITEPAGE_ACTIVATE) {
1489                                         unlock_page(page);
1490                                         ret = 0;
1491                                         continue;
1492                                 }
1493                                 done_index = page->index + 1;
1494                                 done = 1;
1495                                 break;
1496                         } else {
1497                                 nwritten++;
1498                         }
1499
1500                         if (--wbc->nr_to_write <= 0 &&
1501                             wbc->sync_mode == WB_SYNC_NONE) {
1502                                 done = 1;
1503                                 break;
1504                         }
1505                 }
1506                 pagevec_release(&pvec);
1507                 cond_resched();
1508         }
1509
1510         if (!cycled && !done) {
1511                 cycled = 1;
1512                 index = 0;
1513                 end = writeback_index - 1;
1514                 goto retry;
1515         }
1516         if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
1517                 mapping->writeback_index = done_index;
1518
1519         if (nwritten)
1520                 f2fs_submit_merged_bio_cond(F2FS_M_SB(mapping), mapping->host,
1521                                                         NULL, 0, DATA, WRITE);
1522
1523         return ret;
1524 }
1525
1526 static int f2fs_write_data_pages(struct address_space *mapping,
1527                             struct writeback_control *wbc)
1528 {
1529         struct inode *inode = mapping->host;
1530         struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
1531         struct blk_plug plug;
1532         int ret;
1533
1534         /* deal with chardevs and other special file */
1535         if (!mapping->a_ops->writepage)
1536                 return 0;
1537
1538         /* skip writing if there is no dirty page in this inode */
1539         if (!get_dirty_pages(inode) && wbc->sync_mode == WB_SYNC_NONE)
1540                 return 0;
1541
1542         if (S_ISDIR(inode->i_mode) && wbc->sync_mode == WB_SYNC_NONE &&
1543                         get_dirty_pages(inode) < nr_pages_to_skip(sbi, DATA) &&
1544                         available_free_memory(sbi, DIRTY_DENTS))
1545                 goto skip_write;
1546
1547         /* skip writing during file defragment */
1548         if (is_inode_flag_set(inode, FI_DO_DEFRAG))
1549                 goto skip_write;
1550
1551         /* during POR, we don't need to trigger writepage at all. */
1552         if (unlikely(is_sbi_flag_set(sbi, SBI_POR_DOING)))
1553                 goto skip_write;
1554
1555         trace_f2fs_writepages(mapping->host, wbc, DATA);
1556
1557         blk_start_plug(&plug);
1558         ret = f2fs_write_cache_pages(mapping, wbc);
1559         blk_finish_plug(&plug);
1560         /*
1561          * if some pages were truncated, we cannot guarantee its mapping->host
1562          * to detect pending bios.
1563          */
1564
1565         remove_dirty_inode(inode);
1566         return ret;
1567
1568 skip_write:
1569         wbc->pages_skipped += get_dirty_pages(inode);
1570         trace_f2fs_writepages(mapping->host, wbc, DATA);
1571         return 0;
1572 }
1573
1574 static void f2fs_write_failed(struct address_space *mapping, loff_t to)
1575 {
1576         struct inode *inode = mapping->host;
1577         loff_t i_size = i_size_read(inode);
1578
1579         if (to > i_size) {
1580                 truncate_pagecache(inode, i_size);
1581                 truncate_blocks(inode, i_size, true);
1582         }
1583 }
1584
1585 static int prepare_write_begin(struct f2fs_sb_info *sbi,
1586                         struct page *page, loff_t pos, unsigned len,
1587                         block_t *blk_addr, bool *node_changed)
1588 {
1589         struct inode *inode = page->mapping->host;
1590         pgoff_t index = page->index;
1591         struct dnode_of_data dn;
1592         struct page *ipage;
1593         bool locked = false;
1594         struct extent_info ei;
1595         int err = 0;
1596
1597         /*
1598          * we already allocated all the blocks, so we don't need to get
1599          * the block addresses when there is no need to fill the page.
1600          */
1601         if (!f2fs_has_inline_data(inode) && len == PAGE_SIZE)
1602                 return 0;
1603
1604         if (f2fs_has_inline_data(inode) ||
1605                         (pos & PAGE_MASK) >= i_size_read(inode)) {
1606                 f2fs_lock_op(sbi);
1607                 locked = true;
1608         }
1609 restart:
1610         /* check inline_data */
1611         ipage = get_node_page(sbi, inode->i_ino);
1612         if (IS_ERR(ipage)) {
1613                 err = PTR_ERR(ipage);
1614                 goto unlock_out;
1615         }
1616
1617         set_new_dnode(&dn, inode, ipage, ipage, 0);
1618
1619         if (f2fs_has_inline_data(inode)) {
1620                 if (pos + len <= MAX_INLINE_DATA) {
1621                         read_inline_data(page, ipage);
1622                         set_inode_flag(inode, FI_DATA_EXIST);
1623                         if (inode->i_nlink)
1624                                 set_inline_node(ipage);
1625                 } else {
1626                         err = f2fs_convert_inline_page(&dn, page);
1627                         if (err)
1628                                 goto out;
1629                         if (dn.data_blkaddr == NULL_ADDR)
1630                                 err = f2fs_get_block(&dn, index);
1631                 }
1632         } else if (locked) {
1633                 err = f2fs_get_block(&dn, index);
1634         } else {
1635                 if (f2fs_lookup_extent_cache(inode, index, &ei)) {
1636                         dn.data_blkaddr = ei.blk + index - ei.fofs;
1637                 } else {
1638                         /* hole case */
1639                         err = get_dnode_of_data(&dn, index, LOOKUP_NODE);
1640                         if (err || dn.data_blkaddr == NULL_ADDR) {
1641                                 f2fs_put_dnode(&dn);
1642                                 f2fs_lock_op(sbi);
1643                                 locked = true;
1644                                 goto restart;
1645                         }
1646                 }
1647         }
1648
1649         /* convert_inline_page can make node_changed */
1650         *blk_addr = dn.data_blkaddr;
1651         *node_changed = dn.node_changed;
1652 out:
1653         f2fs_put_dnode(&dn);
1654 unlock_out:
1655         if (locked)
1656                 f2fs_unlock_op(sbi);
1657         return err;
1658 }
1659
1660 static int f2fs_write_begin(struct file *file, struct address_space *mapping,
1661                 loff_t pos, unsigned len, unsigned flags,
1662                 struct page **pagep, void **fsdata)
1663 {
1664         struct inode *inode = mapping->host;
1665         struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
1666         struct page *page = NULL;
1667         pgoff_t index = ((unsigned long long) pos) >> PAGE_SHIFT;
1668         bool need_balance = false;
1669         block_t blkaddr = NULL_ADDR;
1670         int err = 0;
1671
1672         trace_f2fs_write_begin(inode, pos, len, flags);
1673
1674         /*
1675          * We should check this at this moment to avoid deadlock on inode page
1676          * and #0 page. The locking rule for inline_data conversion should be:
1677          * lock_page(page #0) -> lock_page(inode_page)
1678          */
1679         if (index != 0) {
1680                 err = f2fs_convert_inline_inode(inode);
1681                 if (err)
1682                         goto fail;
1683         }
1684 repeat:
1685         page = grab_cache_page_write_begin(mapping, index, flags);
1686         if (!page) {
1687                 err = -ENOMEM;
1688                 goto fail;
1689         }
1690
1691         *pagep = page;
1692
1693         err = prepare_write_begin(sbi, page, pos, len,
1694                                         &blkaddr, &need_balance);
1695         if (err)
1696                 goto fail;
1697
1698         if (need_balance && has_not_enough_free_secs(sbi, 0, 0)) {
1699                 unlock_page(page);
1700                 f2fs_balance_fs(sbi, true);
1701                 lock_page(page);
1702                 if (page->mapping != mapping) {
1703                         /* The page got truncated from under us */
1704                         f2fs_put_page(page, 1);
1705                         goto repeat;
1706                 }
1707         }
1708
1709         f2fs_wait_on_page_writeback(page, DATA, false);
1710
1711         /* wait for GCed encrypted page writeback */
1712         if (f2fs_encrypted_inode(inode) && S_ISREG(inode->i_mode))
1713                 f2fs_wait_on_encrypted_page_writeback(sbi, blkaddr);
1714
1715         if (len == PAGE_SIZE || PageUptodate(page))
1716                 return 0;
1717
1718         if (blkaddr == NEW_ADDR) {
1719                 zero_user_segment(page, 0, PAGE_SIZE);
1720                 SetPageUptodate(page);
1721         } else {
1722                 struct bio *bio;
1723
1724                 bio = f2fs_grab_bio(inode, blkaddr, 1);
1725                 if (IS_ERR(bio)) {
1726                         err = PTR_ERR(bio);
1727                         goto fail;
1728                 }
1729                 bio->bi_opf = REQ_OP_READ;
1730                 if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE) {
1731                         bio_put(bio);
1732                         err = -EFAULT;
1733                         goto fail;
1734                 }
1735
1736                 __submit_bio(sbi, bio, DATA);
1737
1738                 lock_page(page);
1739                 if (unlikely(page->mapping != mapping)) {
1740                         f2fs_put_page(page, 1);
1741                         goto repeat;
1742                 }
1743                 if (unlikely(!PageUptodate(page))) {
1744                         err = -EIO;
1745                         goto fail;
1746                 }
1747         }
1748         return 0;
1749
1750 fail:
1751         f2fs_put_page(page, 1);
1752         f2fs_write_failed(mapping, pos + len);
1753         return err;
1754 }
1755
1756 static int f2fs_write_end(struct file *file,
1757                         struct address_space *mapping,
1758                         loff_t pos, unsigned len, unsigned copied,
1759                         struct page *page, void *fsdata)
1760 {
1761         struct inode *inode = page->mapping->host;
1762
1763         trace_f2fs_write_end(inode, pos, len, copied);
1764
1765         /*
1766          * This should be come from len == PAGE_SIZE, and we expect copied
1767          * should be PAGE_SIZE. Otherwise, we treat it with zero copied and
1768          * let generic_perform_write() try to copy data again through copied=0.
1769          */
1770         if (!PageUptodate(page)) {
1771                 if (unlikely(copied != PAGE_SIZE))
1772                         copied = 0;
1773                 else
1774                         SetPageUptodate(page);
1775         }
1776         if (!copied)
1777                 goto unlock_out;
1778
1779         set_page_dirty(page);
1780
1781         if (pos + copied > i_size_read(inode))
1782                 f2fs_i_size_write(inode, pos + copied);
1783 unlock_out:
1784         f2fs_put_page(page, 1);
1785         f2fs_update_time(F2FS_I_SB(inode), REQ_TIME);
1786         return copied;
1787 }
1788
1789 static int check_direct_IO(struct inode *inode, struct iov_iter *iter,
1790                            loff_t offset)
1791 {
1792         unsigned blocksize_mask = inode->i_sb->s_blocksize - 1;
1793
1794         if (offset & blocksize_mask)
1795                 return -EINVAL;
1796
1797         if (iov_iter_alignment(iter) & blocksize_mask)
1798                 return -EINVAL;
1799
1800         return 0;
1801 }
1802
1803 static ssize_t f2fs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
1804 {
1805         struct address_space *mapping = iocb->ki_filp->f_mapping;
1806         struct inode *inode = mapping->host;
1807         size_t count = iov_iter_count(iter);
1808         loff_t offset = iocb->ki_pos;
1809         int rw = iov_iter_rw(iter);
1810         int err;
1811
1812         err = check_direct_IO(inode, iter, offset);
1813         if (err)
1814                 return err;
1815
1816         if (__force_buffered_io(inode, rw))
1817                 return 0;
1818
1819         trace_f2fs_direct_IO_enter(inode, offset, count, rw);
1820
1821         down_read(&F2FS_I(inode)->dio_rwsem[rw]);
1822         err = blockdev_direct_IO(iocb, inode, iter, get_data_block_dio);
1823         up_read(&F2FS_I(inode)->dio_rwsem[rw]);
1824
1825         if (rw == WRITE) {
1826                 if (err > 0)
1827                         set_inode_flag(inode, FI_UPDATE_WRITE);
1828                 else if (err < 0)
1829                         f2fs_write_failed(mapping, offset + count);
1830         }
1831
1832         trace_f2fs_direct_IO_exit(inode, offset, count, rw, err);
1833
1834         return err;
1835 }
1836
1837 void f2fs_invalidate_page(struct page *page, unsigned int offset,
1838                                                         unsigned int length)
1839 {
1840         struct inode *inode = page->mapping->host;
1841         struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
1842
1843         if (inode->i_ino >= F2FS_ROOT_INO(sbi) &&
1844                 (offset % PAGE_SIZE || length != PAGE_SIZE))
1845                 return;
1846
1847         if (PageDirty(page)) {
1848                 if (inode->i_ino == F2FS_META_INO(sbi)) {
1849                         dec_page_count(sbi, F2FS_DIRTY_META);
1850                 } else if (inode->i_ino == F2FS_NODE_INO(sbi)) {
1851                         dec_page_count(sbi, F2FS_DIRTY_NODES);
1852                 } else {
1853                         inode_dec_dirty_pages(inode);
1854                         remove_dirty_inode(inode);
1855                 }
1856         }
1857
1858         /* This is atomic written page, keep Private */
1859         if (IS_ATOMIC_WRITTEN_PAGE(page))
1860                 return;
1861
1862         set_page_private(page, 0);
1863         ClearPagePrivate(page);
1864 }
1865
1866 int f2fs_release_page(struct page *page, gfp_t wait)
1867 {
1868         /* If this is dirty page, keep PagePrivate */
1869         if (PageDirty(page))
1870                 return 0;
1871
1872         /* This is atomic written page, keep Private */
1873         if (IS_ATOMIC_WRITTEN_PAGE(page))
1874                 return 0;
1875
1876         set_page_private(page, 0);
1877         ClearPagePrivate(page);
1878         return 1;
1879 }
1880
1881 /*
1882  * This was copied from __set_page_dirty_buffers which gives higher performance
1883  * in very high speed storages. (e.g., pmem)
1884  */
1885 void f2fs_set_page_dirty_nobuffers(struct page *page)
1886 {
1887         struct address_space *mapping = page->mapping;
1888         unsigned long flags;
1889
1890         if (unlikely(!mapping))
1891                 return;
1892
1893         spin_lock(&mapping->private_lock);
1894         lock_page_memcg(page);
1895         SetPageDirty(page);
1896         spin_unlock(&mapping->private_lock);
1897
1898         spin_lock_irqsave(&mapping->tree_lock, flags);
1899         WARN_ON_ONCE(!PageUptodate(page));
1900         account_page_dirtied(page, mapping);
1901         radix_tree_tag_set(&mapping->page_tree,
1902                         page_index(page), PAGECACHE_TAG_DIRTY);
1903         spin_unlock_irqrestore(&mapping->tree_lock, flags);
1904         unlock_page_memcg(page);
1905
1906         __mark_inode_dirty(mapping->host, I_DIRTY_PAGES);
1907         return;
1908 }
1909
1910 static int f2fs_set_data_page_dirty(struct page *page)
1911 {
1912         struct address_space *mapping = page->mapping;
1913         struct inode *inode = mapping->host;
1914
1915         trace_f2fs_set_page_dirty(page, DATA);
1916
1917         if (!PageUptodate(page))
1918                 SetPageUptodate(page);
1919
1920         if (f2fs_is_atomic_file(inode)) {
1921                 if (!IS_ATOMIC_WRITTEN_PAGE(page)) {
1922                         register_inmem_page(inode, page);
1923                         return 1;
1924                 }
1925                 /*
1926                  * Previously, this page has been registered, we just
1927                  * return here.
1928                  */
1929                 return 0;
1930         }
1931
1932         if (!PageDirty(page)) {
1933                 f2fs_set_page_dirty_nobuffers(page);
1934                 update_dirty_page(inode, page);
1935                 return 1;
1936         }
1937         return 0;
1938 }
1939
1940 static sector_t f2fs_bmap(struct address_space *mapping, sector_t block)
1941 {
1942         struct inode *inode = mapping->host;
1943
1944         if (f2fs_has_inline_data(inode))
1945                 return 0;
1946
1947         /* make sure allocating whole blocks */
1948         if (mapping_tagged(mapping, PAGECACHE_TAG_DIRTY))
1949                 filemap_write_and_wait(mapping);
1950
1951         return generic_block_bmap(mapping, block, get_data_block_bmap);
1952 }
1953
1954 #ifdef CONFIG_MIGRATION
1955 #include <linux/migrate.h>
1956
1957 int f2fs_migrate_page(struct address_space *mapping,
1958                 struct page *newpage, struct page *page, enum migrate_mode mode)
1959 {
1960         int rc, extra_count;
1961         struct f2fs_inode_info *fi = F2FS_I(mapping->host);
1962         bool atomic_written = IS_ATOMIC_WRITTEN_PAGE(page);
1963
1964         BUG_ON(PageWriteback(page));
1965
1966         /* migrating an atomic written page is safe with the inmem_lock hold */
1967         if (atomic_written && !mutex_trylock(&fi->inmem_lock))
1968                 return -EAGAIN;
1969
1970         /*
1971          * A reference is expected if PagePrivate set when move mapping,
1972          * however F2FS breaks this for maintaining dirty page counts when
1973          * truncating pages. So here adjusting the 'extra_count' make it work.
1974          */
1975         extra_count = (atomic_written ? 1 : 0) - page_has_private(page);
1976         rc = migrate_page_move_mapping(mapping, newpage,
1977                                 page, NULL, mode, extra_count);
1978         if (rc != MIGRATEPAGE_SUCCESS) {
1979                 if (atomic_written)
1980                         mutex_unlock(&fi->inmem_lock);
1981                 return rc;
1982         }
1983
1984         if (atomic_written) {
1985                 struct inmem_pages *cur;
1986                 list_for_each_entry(cur, &fi->inmem_pages, list)
1987                         if (cur->page == page) {
1988                                 cur->page = newpage;
1989                                 break;
1990                         }
1991                 mutex_unlock(&fi->inmem_lock);
1992                 put_page(page);
1993                 get_page(newpage);
1994         }
1995
1996         if (PagePrivate(page))
1997                 SetPagePrivate(newpage);
1998         set_page_private(newpage, page_private(page));
1999
2000         migrate_page_copy(newpage, page);
2001
2002         return MIGRATEPAGE_SUCCESS;
2003 }
2004 #endif
2005
2006 const struct address_space_operations f2fs_dblock_aops = {
2007         .readpage       = f2fs_read_data_page,
2008         .readpages      = f2fs_read_data_pages,
2009         .writepage      = f2fs_write_data_page,
2010         .writepages     = f2fs_write_data_pages,
2011         .write_begin    = f2fs_write_begin,
2012         .write_end      = f2fs_write_end,
2013         .set_page_dirty = f2fs_set_data_page_dirty,
2014         .invalidatepage = f2fs_invalidate_page,
2015         .releasepage    = f2fs_release_page,
2016         .direct_IO      = f2fs_direct_IO,
2017         .bmap           = f2fs_bmap,
2018 #ifdef CONFIG_MIGRATION
2019         .migratepage    = f2fs_migrate_page,
2020 #endif
2021 };