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 #include <linux/sched/signal.h>
  26
  27 #include "f2fs.h"
  28 #include "node.h"
  29 #include "segment.h"
  30 #include "trace.h"
  31 #include <trace/events/f2fs.h>
  32
  33 static bool __is_cp_guaranteed(struct page *page)
  34 {
  35         struct address_space *mapping = page->mapping;
  36         struct inode *inode;
  37         struct f2fs_sb_info *sbi;
  38
  39         if (!mapping)
  40                 return false;
  41
  42         inode = mapping->host;
  43         sbi = F2FS_I_SB(inode);
  44
  45         if (inode->i_ino == F2FS_META_INO(sbi) ||
  46                         inode->i_ino ==  F2FS_NODE_INO(sbi) ||
  47                         S_ISDIR(inode->i_mode) ||
  48                         is_cold_data(page))
  49                 return true;
  50         return false;
  51 }
  52
  53 static void f2fs_read_end_io(struct bio *bio)
  54 {
  55         struct bio_vec *bvec;
  56         int i;
  57
  58 #ifdef CONFIG_F2FS_FAULT_INJECTION
  59         if (time_to_inject(F2FS_P_SB(bio->bi_io_vec->bv_page), FAULT_IO)) {
  60                 f2fs_show_injection_info(FAULT_IO);
  61                 bio->bi_status = BLK_STS_IOERR;
  62         }
  63 #endif
  64
  65         if (f2fs_bio_encrypted(bio)) {
  66                 if (bio->bi_status) {
  67                         fscrypt_release_ctx(bio->bi_private);
  68                 } else {
  69                         fscrypt_decrypt_bio_pages(bio->bi_private, bio);
  70                         return;
  71                 }
  72         }
  73
  74         bio_for_each_segment_all(bvec, bio, i) {
  75                 struct page *page = bvec->bv_page;
  76
  77                 if (!bio->bi_status) {
  78                         if (!PageUptodate(page))
  79                                 SetPageUptodate(page);
  80                 } else {
  81                         ClearPageUptodate(page);
  82                         SetPageError(page);
  83                 }
  84                 unlock_page(page);
  85         }
  86         bio_put(bio);
  87 }
  88
  89 static void f2fs_write_end_io(struct bio *bio)
  90 {
  91         struct f2fs_sb_info *sbi = bio->bi_private;
  92         struct bio_vec *bvec;
  93         int i;
  94
  95         bio_for_each_segment_all(bvec, bio, i) {
  96                 struct page *page = bvec->bv_page;
  97                 enum count_type type = WB_DATA_TYPE(page);
  98
  99                 if (IS_DUMMY_WRITTEN_PAGE(page)) {
 100                         set_page_private(page, (unsigned long)NULL);
 101                         ClearPagePrivate(page);
 102                         unlock_page(page);
 103                         mempool_free(page, sbi->write_io_dummy);
 104
 105                         if (unlikely(bio->bi_status))
 106                                 f2fs_stop_checkpoint(sbi, true);
 107                         continue;
 108                 }
 109
 110                 fscrypt_pullback_bio_page(&page, true);
 111
 112                 if (unlikely(bio->bi_status)) {
 113                         mapping_set_error(page->mapping, -EIO);
 114                         f2fs_stop_checkpoint(sbi, true);
 115                 }
 116                 dec_page_count(sbi, type);
 117                 clear_cold_data(page);
 118                 end_page_writeback(page);
 119         }
 120         if (!get_pages(sbi, F2FS_WB_CP_DATA) &&
 121                                 wq_has_sleeper(&sbi->cp_wait))
 122                 wake_up(&sbi->cp_wait);
 123
 124         bio_put(bio);
 125 }
 126
 127 /*
 128  * Return true, if pre_bio's bdev is same as its target device.
 129  */
 130 struct block_device *f2fs_target_device(struct f2fs_sb_info *sbi,
 131                                 block_t blk_addr, struct bio *bio)
 132 {
 133         struct block_device *bdev = sbi->sb->s_bdev;
 134         int i;
 135
 136         for (i = 0; i < sbi->s_ndevs; i++) {
 137                 if (FDEV(i).start_blk <= blk_addr &&
 138                                         FDEV(i).end_blk >= blk_addr) {
 139                         blk_addr -= FDEV(i).start_blk;
 140                         bdev = FDEV(i).bdev;
 141                         break;
 142                 }
 143         }
 144         if (bio) {
 145                 bio->bi_bdev = bdev;
 146                 bio->bi_iter.bi_sector = SECTOR_FROM_BLOCK(blk_addr);
 147         }
 148         return bdev;
 149 }
 150
 151 int f2fs_target_device_index(struct f2fs_sb_info *sbi, block_t blkaddr)
 152 {
 153         int i;
 154
 155         for (i = 0; i < sbi->s_ndevs; i++)
 156                 if (FDEV(i).start_blk <= blkaddr && FDEV(i).end_blk >= blkaddr)
 157                         return i;
 158         return 0;
 159 }
 160
 161 static bool __same_bdev(struct f2fs_sb_info *sbi,
 162                                 block_t blk_addr, struct bio *bio)
 163 {
 164         return f2fs_target_device(sbi, blk_addr, NULL) == bio->bi_bdev;
 165 }
 166
 167 /*
 168  * Low-level block read/write IO operations.
 169  */
 170 static struct bio *__bio_alloc(struct f2fs_sb_info *sbi, block_t blk_addr,
 171                                 int npages, bool is_read)
 172 {
 173         struct bio *bio;
 174
 175         bio = f2fs_bio_alloc(npages);
 176
 177         f2fs_target_device(sbi, blk_addr, bio);
 178         bio->bi_end_io = is_read ? f2fs_read_end_io : f2fs_write_end_io;
 179         bio->bi_private = is_read ? NULL : sbi;
 180
 181         return bio;
 182 }
 183
 184 static inline void __submit_bio(struct f2fs_sb_info *sbi,
 185                                 struct bio *bio, enum page_type type)
 186 {
 187         if (!is_read_io(bio_op(bio))) {
 188                 unsigned int start;
 189
 190                 if (f2fs_sb_mounted_blkzoned(sbi->sb) &&
 191                         current->plug && (type == DATA || type == NODE))
 192                         blk_finish_plug(current->plug);
 193
 194                 if (type != DATA && type != NODE)
 195                         goto submit_io;
 196
 197                 start = bio->bi_iter.bi_size >> F2FS_BLKSIZE_BITS;
 198                 start %= F2FS_IO_SIZE(sbi);
 199
 200                 if (start == 0)
 201                         goto submit_io;
 202
 203                 /* fill dummy pages */
 204                 for (; start < F2FS_IO_SIZE(sbi); start++) {
 205                         struct page *page =
 206                                 mempool_alloc(sbi->write_io_dummy,
 207                                         GFP_NOIO | __GFP_ZERO | __GFP_NOFAIL);
 208                         f2fs_bug_on(sbi, !page);
 209
 210                         SetPagePrivate(page);
 211                         set_page_private(page, (unsigned long)DUMMY_WRITTEN_PAGE);
 212                         lock_page(page);
 213                         if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE)
 214                                 f2fs_bug_on(sbi, 1);
 215                 }
 216                 /*
 217                  * In the NODE case, we lose next block address chain. So, we
 218                  * need to do checkpoint in f2fs_sync_file.
 219                  */
 220                 if (type == NODE)
 221                         set_sbi_flag(sbi, SBI_NEED_CP);
 222         }
 223 submit_io:
 224         if (is_read_io(bio_op(bio)))
 225                 trace_f2fs_submit_read_bio(sbi->sb, type, bio);
 226         else
 227                 trace_f2fs_submit_write_bio(sbi->sb, type, bio);
 228         submit_bio(bio);
 229 }
 230
 231 static void __submit_merged_bio(struct f2fs_bio_info *io)
 232 {
 233         struct f2fs_io_info *fio = &io->fio;
 234
 235         if (!io->bio)
 236                 return;
 237
 238         bio_set_op_attrs(io->bio, fio->op, fio->op_flags);
 239
 240         if (is_read_io(fio->op))
 241                 trace_f2fs_prepare_read_bio(io->sbi->sb, fio->type, io->bio);
 242         else
 243                 trace_f2fs_prepare_write_bio(io->sbi->sb, fio->type, io->bio);
 244
 245         __submit_bio(io->sbi, io->bio, fio->type);
 246         io->bio = NULL;
 247 }
 248
 249 static bool __has_merged_page(struct f2fs_bio_info *io,
 250                                 struct inode *inode, nid_t ino, pgoff_t idx)
 251 {
 252         struct bio_vec *bvec;
 253         struct page *target;
 254         int i;
 255
 256         if (!io->bio)
 257                 return false;
 258
 259         if (!inode && !ino)
 260                 return true;
 261
 262         bio_for_each_segment_all(bvec, io->bio, i) {
 263
 264                 if (bvec->bv_page->mapping)
 265                         target = bvec->bv_page;
 266                 else
 267                         target = fscrypt_control_page(bvec->bv_page);
 268
 269                 if (idx != target->index)
 270                         continue;
 271
 272                 if (inode && inode == target->mapping->host)
 273                         return true;
 274                 if (ino && ino == ino_of_node(target))
 275                         return true;
 276         }
 277
 278         return false;
 279 }
 280
 281 static bool has_merged_page(struct f2fs_sb_info *sbi, struct inode *inode,
 282                                 nid_t ino, pgoff_t idx, enum page_type type)
 283 {
 284         enum page_type btype = PAGE_TYPE_OF_BIO(type);
 285         enum temp_type temp;
 286         struct f2fs_bio_info *io;
 287         bool ret = false;
 288
 289         for (temp = HOT; temp < NR_TEMP_TYPE; temp++) {
 290                 io = sbi->write_io[btype] + temp;
 291
 292                 down_read(&io->io_rwsem);
 293                 ret = __has_merged_page(io, inode, ino, idx);
 294                 up_read(&io->io_rwsem);
 295
 296                 /* TODO: use HOT temp only for meta pages now. */
 297                 if (ret || btype == META)
 298                         break;
 299         }
 300         return ret;
 301 }
 302
 303 static void __f2fs_submit_merged_write(struct f2fs_sb_info *sbi,
 304                                 enum page_type type, enum temp_type temp)
 305 {
 306         enum page_type btype = PAGE_TYPE_OF_BIO(type);
 307         struct f2fs_bio_info *io = sbi->write_io[btype] + temp;
 308
 309         down_write(&io->io_rwsem);
 310
 311         /* change META to META_FLUSH in the checkpoint procedure */
 312         if (type >= META_FLUSH) {
 313                 io->fio.type = META_FLUSH;
 314                 io->fio.op = REQ_OP_WRITE;
 315                 io->fio.op_flags = REQ_META | REQ_PRIO | REQ_SYNC;
 316                 if (!test_opt(sbi, NOBARRIER))
 317                         io->fio.op_flags |= REQ_PREFLUSH | REQ_FUA;
 318         }
 319         __submit_merged_bio(io);
 320         up_write(&io->io_rwsem);
 321 }
 322
 323 static void __submit_merged_write_cond(struct f2fs_sb_info *sbi,
 324                                 struct inode *inode, nid_t ino, pgoff_t idx,
 325                                 enum page_type type, bool force)
 326 {
 327         enum temp_type temp;
 328
 329         if (!force && !has_merged_page(sbi, inode, ino, idx, type))
 330                 return;
 331
 332         for (temp = HOT; temp < NR_TEMP_TYPE; temp++) {
 333
 334                 __f2fs_submit_merged_write(sbi, type, temp);
 335
 336                 /* TODO: use HOT temp only for meta pages now. */
 337                 if (type >= META)
 338                         break;
 339         }
 340 }
 341
 342 void f2fs_submit_merged_write(struct f2fs_sb_info *sbi, enum page_type type)
 343 {
 344         __submit_merged_write_cond(sbi, NULL, 0, 0, type, true);
 345 }
 346
 347 void f2fs_submit_merged_write_cond(struct f2fs_sb_info *sbi,
 348                                 struct inode *inode, nid_t ino, pgoff_t idx,
 349                                 enum page_type type)
 350 {
 351         __submit_merged_write_cond(sbi, inode, ino, idx, type, false);
 352 }
 353
 354 void f2fs_flush_merged_writes(struct f2fs_sb_info *sbi)
 355 {
 356         f2fs_submit_merged_write(sbi, DATA);
 357         f2fs_submit_merged_write(sbi, NODE);
 358         f2fs_submit_merged_write(sbi, META);
 359 }
 360
 361 /*
 362  * Fill the locked page with data located in the block address.
 363  * A caller needs to unlock the page on failure.
 364  */
 365 int f2fs_submit_page_bio(struct f2fs_io_info *fio)
 366 {
 367         struct bio *bio;
 368         struct page *page = fio->encrypted_page ?
 369                         fio->encrypted_page : fio->page;
 370
 371         trace_f2fs_submit_page_bio(page, fio);
 372         f2fs_trace_ios(fio, 0);
 373
 374         /* Allocate a new bio */
 375         bio = __bio_alloc(fio->sbi, fio->new_blkaddr, 1, is_read_io(fio->op));
 376
 377         if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE) {
 378                 bio_put(bio);
 379                 return -EFAULT;
 380         }
 381         bio_set_op_attrs(bio, fio->op, fio->op_flags);
 382
 383         __submit_bio(fio->sbi, bio, fio->type);
 384
 385         if (!is_read_io(fio->op))
 386                 inc_page_count(fio->sbi, WB_DATA_TYPE(fio->page));
 387         return 0;
 388 }
 389
 390 int f2fs_submit_page_write(struct f2fs_io_info *fio)
 391 {
 392         struct f2fs_sb_info *sbi = fio->sbi;
 393         enum page_type btype = PAGE_TYPE_OF_BIO(fio->type);
 394         struct f2fs_bio_info *io = sbi->write_io[btype] + fio->temp;
 395         struct page *bio_page;
 396         int err = 0;
 397
 398         f2fs_bug_on(sbi, is_read_io(fio->op));
 399
 400         down_write(&io->io_rwsem);
 401 next:
 402         if (fio->in_list) {
 403                 spin_lock(&io->io_lock);
 404                 if (list_empty(&io->io_list)) {
 405                         spin_unlock(&io->io_lock);
 406                         goto out_fail;
 407                 }
 408                 fio = list_first_entry(&io->io_list,
 409                                                 struct f2fs_io_info, list);
 410                 list_del(&fio->list);
 411                 spin_unlock(&io->io_lock);
 412         }
 413
 414         if (fio->old_blkaddr != NEW_ADDR)
 415                 verify_block_addr(sbi, fio->old_blkaddr);
 416         verify_block_addr(sbi, fio->new_blkaddr);
 417
 418         bio_page = fio->encrypted_page ? fio->encrypted_page : fio->page;
 419
 420         /* set submitted = 1 as a return value */
 421         fio->submitted = 1;
 422
 423         inc_page_count(sbi, WB_DATA_TYPE(bio_page));
 424
 425         if (io->bio && (io->last_block_in_bio != fio->new_blkaddr - 1 ||
 426             (io->fio.op != fio->op || io->fio.op_flags != fio->op_flags) ||
 427                         !__same_bdev(sbi, fio->new_blkaddr, io->bio)))
 428                 __submit_merged_bio(io);
 429 alloc_new:
 430         if (io->bio == NULL) {
 431                 if ((fio->type == DATA || fio->type == NODE) &&
 432                                 fio->new_blkaddr & F2FS_IO_SIZE_MASK(sbi)) {
 433                         err = -EAGAIN;
 434                         dec_page_count(sbi, WB_DATA_TYPE(bio_page));
 435                         goto out_fail;
 436                 }
 437                 io->bio = __bio_alloc(sbi, fio->new_blkaddr,
 438                                                 BIO_MAX_PAGES, false);
 439                 io->fio = *fio;
 440         }
 441
 442         if (bio_add_page(io->bio, bio_page, PAGE_SIZE, 0) < PAGE_SIZE) {
 443                 __submit_merged_bio(io);
 444                 goto alloc_new;
 445         }
 446
 447         io->last_block_in_bio = fio->new_blkaddr;
 448         f2fs_trace_ios(fio, 0);
 449
 450         trace_f2fs_submit_page_write(fio->page, fio);
 451
 452         if (fio->in_list)
 453                 goto next;
 454 out_fail:
 455         up_write(&io->io_rwsem);
 456         return err;
 457 }
 458
 459 static void __set_data_blkaddr(struct dnode_of_data *dn)
 460 {
 461         struct f2fs_node *rn = F2FS_NODE(dn->node_page);
 462         __le32 *addr_array;
 463         int base = 0;
 464
 465         if (IS_INODE(dn->node_page) && f2fs_has_extra_attr(dn->inode))
 466                 base = get_extra_isize(dn->inode);
 467
 468         /* Get physical address of data block */
 469         addr_array = blkaddr_in_node(rn);
 470         addr_array[base + dn->ofs_in_node] = cpu_to_le32(dn->data_blkaddr);
 471 }
 472
 473 /*
 474  * Lock ordering for the change of data block address:
 475  * ->data_page
 476  *  ->node_page
 477  *    update block addresses in the node page
 478  */
 479 void set_data_blkaddr(struct dnode_of_data *dn)
 480 {
 481         f2fs_wait_on_page_writeback(dn->node_page, NODE, true);
 482         __set_data_blkaddr(dn);
 483         if (set_page_dirty(dn->node_page))
 484                 dn->node_changed = true;
 485 }
 486
 487 void f2fs_update_data_blkaddr(struct dnode_of_data *dn, block_t blkaddr)
 488 {
 489         dn->data_blkaddr = blkaddr;
 490         set_data_blkaddr(dn);
 491         f2fs_update_extent_cache(dn);
 492 }
 493
 494 /* dn->ofs_in_node will be returned with up-to-date last block pointer */
 495 int reserve_new_blocks(struct dnode_of_data *dn, blkcnt_t count)
 496 {
 497         struct f2fs_sb_info *sbi = F2FS_I_SB(dn->inode);
 498         int err;
 499
 500         if (!count)
 501                 return 0;
 502
 503         if (unlikely(is_inode_flag_set(dn->inode, FI_NO_ALLOC)))
 504                 return -EPERM;
 505         if (unlikely((err = inc_valid_block_count(sbi, dn->inode, &count))))
 506                 return err;
 507
 508         trace_f2fs_reserve_new_blocks(dn->inode, dn->nid,
 509                                                 dn->ofs_in_node, count);
 510
 511         f2fs_wait_on_page_writeback(dn->node_page, NODE, true);
 512
 513         for (; count > 0; dn->ofs_in_node++) {
 514                 block_t blkaddr = datablock_addr(dn->inode,
 515                                         dn->node_page, dn->ofs_in_node);
 516                 if (blkaddr == NULL_ADDR) {
 517                         dn->data_blkaddr = NEW_ADDR;
 518                         __set_data_blkaddr(dn);
 519                         count--;
 520                 }
 521         }
 522
 523         if (set_page_dirty(dn->node_page))
 524                 dn->node_changed = true;
 525         return 0;
 526 }
 527
 528 /* Should keep dn->ofs_in_node unchanged */
 529 int reserve_new_block(struct dnode_of_data *dn)
 530 {
 531         unsigned int ofs_in_node = dn->ofs_in_node;
 532         int ret;
 533
 534         ret = reserve_new_blocks(dn, 1);
 535         dn->ofs_in_node = ofs_in_node;
 536         return ret;
 537 }
 538
 539 int f2fs_reserve_block(struct dnode_of_data *dn, pgoff_t index)
 540 {
 541         bool need_put = dn->inode_page ? false : true;
 542         int err;
 543
 544         err = get_dnode_of_data(dn, index, ALLOC_NODE);
 545         if (err)
 546                 return err;
 547
 548         if (dn->data_blkaddr == NULL_ADDR)
 549                 err = reserve_new_block(dn);
 550         if (err || need_put)
 551                 f2fs_put_dnode(dn);
 552         return err;
 553 }
 554
 555 int f2fs_get_block(struct dnode_of_data *dn, pgoff_t index)
 556 {
 557         struct extent_info ei  = {0,0,0};
 558         struct inode *inode = dn->inode;
 559
 560         if (f2fs_lookup_extent_cache(inode, index, &ei)) {
 561                 dn->data_blkaddr = ei.blk + index - ei.fofs;
 562                 return 0;
 563         }
 564
 565         return f2fs_reserve_block(dn, index);
 566 }
 567
 568 struct page *get_read_data_page(struct inode *inode, pgoff_t index,
 569                                                 int op_flags, bool for_write)
 570 {
 571         struct address_space *mapping = inode->i_mapping;
 572         struct dnode_of_data dn;
 573         struct page *page;
 574         struct extent_info ei = {0,0,0};
 575         int err;
 576         struct f2fs_io_info fio = {
 577                 .sbi = F2FS_I_SB(inode),
 578                 .type = DATA,
 579                 .op = REQ_OP_READ,
 580                 .op_flags = op_flags,
 581                 .encrypted_page = NULL,
 582         };
 583
 584         if (f2fs_encrypted_file(inode))
 585                 return read_mapping_page(mapping, index, NULL);
 586
 587         page = f2fs_grab_cache_page(mapping, index, for_write);
 588         if (!page)
 589                 return ERR_PTR(-ENOMEM);
 590
 591         if (f2fs_lookup_extent_cache(inode, index, &ei)) {
 592                 dn.data_blkaddr = ei.blk + index - ei.fofs;
 593                 goto got_it;
 594         }
 595
 596         set_new_dnode(&dn, inode, NULL, NULL, 0);
 597         err = get_dnode_of_data(&dn, index, LOOKUP_NODE);
 598         if (err)
 599                 goto put_err;
 600         f2fs_put_dnode(&dn);
 601
 602         if (unlikely(dn.data_blkaddr == NULL_ADDR)) {
 603                 err = -ENOENT;
 604                 goto put_err;
 605         }
 606 got_it:
 607         if (PageUptodate(page)) {
 608                 unlock_page(page);
 609                 return page;
 610         }
 611
 612         /*
 613          * A new dentry page is allocated but not able to be written, since its
 614          * new inode page couldn't be allocated due to -ENOSPC.
 615          * In such the case, its blkaddr can be remained as NEW_ADDR.
 616          * see, f2fs_add_link -> get_new_data_page -> init_inode_metadata.
 617          */
 618         if (dn.data_blkaddr == NEW_ADDR) {
 619                 zero_user_segment(page, 0, PAGE_SIZE);
 620                 if (!PageUptodate(page))
 621                         SetPageUptodate(page);
 622                 unlock_page(page);
 623                 return page;
 624         }
 625
 626         fio.new_blkaddr = fio.old_blkaddr = dn.data_blkaddr;
 627         fio.page = page;
 628         err = f2fs_submit_page_bio(&fio);
 629         if (err)
 630                 goto put_err;
 631         return page;
 632
 633 put_err:
 634         f2fs_put_page(page, 1);
 635         return ERR_PTR(err);
 636 }
 637
 638 struct page *find_data_page(struct inode *inode, pgoff_t index)
 639 {
 640         struct address_space *mapping = inode->i_mapping;
 641         struct page *page;
 642
 643         page = find_get_page(mapping, index);
 644         if (page && PageUptodate(page))
 645                 return page;
 646         f2fs_put_page(page, 0);
 647
 648         page = get_read_data_page(inode, index, 0, false);
 649         if (IS_ERR(page))
 650                 return page;
 651
 652         if (PageUptodate(page))
 653                 return page;
 654
 655         wait_on_page_locked(page);
 656         if (unlikely(!PageUptodate(page))) {
 657                 f2fs_put_page(page, 0);
 658                 return ERR_PTR(-EIO);
 659         }
 660         return page;
 661 }
 662
 663 /*
 664  * If it tries to access a hole, return an error.
 665  * Because, the callers, functions in dir.c and GC, should be able to know
 666  * whether this page exists or not.
 667  */
 668 struct page *get_lock_data_page(struct inode *inode, pgoff_t index,
 669                                                         bool for_write)
 670 {
 671         struct address_space *mapping = inode->i_mapping;
 672         struct page *page;
 673 repeat:
 674         page = get_read_data_page(inode, index, 0, for_write);
 675         if (IS_ERR(page))
 676                 return page;
 677
 678         /* wait for read completion */
 679         lock_page(page);
 680         if (unlikely(page->mapping != mapping)) {
 681                 f2fs_put_page(page, 1);
 682                 goto repeat;
 683         }
 684         if (unlikely(!PageUptodate(page))) {
 685                 f2fs_put_page(page, 1);
 686                 return ERR_PTR(-EIO);
 687         }
 688         return page;
 689 }
 690
 691 /*
 692  * Caller ensures that this data page is never allocated.
 693  * A new zero-filled data page is allocated in the page cache.
 694  *
 695  * Also, caller should grab and release a rwsem by calling f2fs_lock_op() and
 696  * f2fs_unlock_op().
 697  * Note that, ipage is set only by make_empty_dir, and if any error occur,
 698  * ipage should be released by this function.
 699  */
 700 struct page *get_new_data_page(struct inode *inode,
 701                 struct page *ipage, pgoff_t index, bool new_i_size)
 702 {
 703         struct address_space *mapping = inode->i_mapping;
 704         struct page *page;
 705         struct dnode_of_data dn;
 706         int err;
 707
 708         page = f2fs_grab_cache_page(mapping, index, true);
 709         if (!page) {
 710                 /*
 711                  * before exiting, we should make sure ipage will be released
 712                  * if any error occur.
 713                  */
 714                 f2fs_put_page(ipage, 1);
 715                 return ERR_PTR(-ENOMEM);
 716         }
 717
 718         set_new_dnode(&dn, inode, ipage, NULL, 0);
 719         err = f2fs_reserve_block(&dn, index);
 720         if (err) {
 721                 f2fs_put_page(page, 1);
 722                 return ERR_PTR(err);
 723         }
 724         if (!ipage)
 725                 f2fs_put_dnode(&dn);
 726
 727         if (PageUptodate(page))
 728                 goto got_it;
 729
 730         if (dn.data_blkaddr == NEW_ADDR) {
 731                 zero_user_segment(page, 0, PAGE_SIZE);
 732                 if (!PageUptodate(page))
 733                         SetPageUptodate(page);
 734         } else {
 735                 f2fs_put_page(page, 1);
 736
 737                 /* if ipage exists, blkaddr should be NEW_ADDR */
 738                 f2fs_bug_on(F2FS_I_SB(inode), ipage);
 739                 page = get_lock_data_page(inode, index, true);
 740                 if (IS_ERR(page))
 741                         return page;
 742         }
 743 got_it:
 744         if (new_i_size && i_size_read(inode) <
 745                                 ((loff_t)(index + 1) << PAGE_SHIFT))
 746                 f2fs_i_size_write(inode, ((loff_t)(index + 1) << PAGE_SHIFT));
 747         return page;
 748 }
 749
 750 static int __allocate_data_block(struct dnode_of_data *dn)
 751 {
 752         struct f2fs_sb_info *sbi = F2FS_I_SB(dn->inode);
 753         struct f2fs_summary sum;
 754         struct node_info ni;
 755         pgoff_t fofs;
 756         blkcnt_t count = 1;
 757         int err;
 758
 759         if (unlikely(is_inode_flag_set(dn->inode, FI_NO_ALLOC)))
 760                 return -EPERM;
 761
 762         dn->data_blkaddr = datablock_addr(dn->inode,
 763                                 dn->node_page, dn->ofs_in_node);
 764         if (dn->data_blkaddr == NEW_ADDR)
 765                 goto alloc;
 766
 767         if (unlikely((err = inc_valid_block_count(sbi, dn->inode, &count))))
 768                 return err;
 769
 770 alloc:
 771         get_node_info(sbi, dn->nid, &ni);
 772         set_summary(&sum, dn->nid, dn->ofs_in_node, ni.version);
 773
 774         allocate_data_block(sbi, NULL, dn->data_blkaddr, &dn->data_blkaddr,
 775                                         &sum, CURSEG_WARM_DATA, NULL, false);
 776         set_data_blkaddr(dn);
 777
 778         /* update i_size */
 779         fofs = start_bidx_of_node(ofs_of_node(dn->node_page), dn->inode) +
 780                                                         dn->ofs_in_node;
 781         if (i_size_read(dn->inode) < ((loff_t)(fofs + 1) << PAGE_SHIFT))
 782                 f2fs_i_size_write(dn->inode,
 783                                 ((loff_t)(fofs + 1) << PAGE_SHIFT));
 784         return 0;
 785 }
 786
 787 static inline bool __force_buffered_io(struct inode *inode, int rw)
 788 {
 789         return (f2fs_encrypted_file(inode) ||
 790                         (rw == WRITE && test_opt(F2FS_I_SB(inode), LFS)) ||
 791                         F2FS_I_SB(inode)->s_ndevs);
 792 }
 793
 794 int f2fs_preallocate_blocks(struct kiocb *iocb, struct iov_iter *from)
 795 {
 796         struct inode *inode = file_inode(iocb->ki_filp);
 797         struct f2fs_map_blocks map;
 798         int err = 0;
 799
 800         if (is_inode_flag_set(inode, FI_NO_PREALLOC))
 801                 return 0;
 802
 803         map.m_lblk = F2FS_BLK_ALIGN(iocb->ki_pos);
 804         map.m_len = F2FS_BYTES_TO_BLK(iocb->ki_pos + iov_iter_count(from));
 805         if (map.m_len > map.m_lblk)
 806                 map.m_len -= map.m_lblk;
 807         else
 808                 map.m_len = 0;
 809
 810         map.m_next_pgofs = NULL;
 811
 812         if (iocb->ki_flags & IOCB_DIRECT) {
 813                 err = f2fs_convert_inline_inode(inode);
 814                 if (err)
 815                         return err;
 816                 return f2fs_map_blocks(inode, &map, 1,
 817                         __force_buffered_io(inode, WRITE) ?
 818                                 F2FS_GET_BLOCK_PRE_AIO :
 819                                 F2FS_GET_BLOCK_PRE_DIO);
 820         }
 821         if (iocb->ki_pos + iov_iter_count(from) > MAX_INLINE_DATA(inode)) {
 822                 err = f2fs_convert_inline_inode(inode);
 823                 if (err)
 824                         return err;
 825         }
 826         if (!f2fs_has_inline_data(inode))
 827                 return f2fs_map_blocks(inode, &map, 1, F2FS_GET_BLOCK_PRE_AIO);
 828         return err;
 829 }
 830
 831 static inline void __do_map_lock(struct f2fs_sb_info *sbi, int flag, bool lock)
 832 {
 833         if (flag == F2FS_GET_BLOCK_PRE_AIO) {
 834                 if (lock)
 835                         down_read(&sbi->node_change);
 836                 else
 837                         up_read(&sbi->node_change);
 838         } else {
 839                 if (lock)
 840                         f2fs_lock_op(sbi);
 841                 else
 842                         f2fs_unlock_op(sbi);
 843         }
 844 }
 845
 846 /*
 847  * f2fs_map_blocks() now supported readahead/bmap/rw direct_IO with
 848  * f2fs_map_blocks structure.
 849  * If original data blocks are allocated, then give them to blockdev.
 850  * Otherwise,
 851  *     a. preallocate requested block addresses
 852  *     b. do not use extent cache for better performance
 853  *     c. give the block addresses to blockdev
 854  */
 855 int f2fs_map_blocks(struct inode *inode, struct f2fs_map_blocks *map,
 856                                                 int create, int flag)
 857 {
 858         unsigned int maxblocks = map->m_len;
 859         struct dnode_of_data dn;
 860         struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
 861         int mode = create ? ALLOC_NODE : LOOKUP_NODE;
 862         pgoff_t pgofs, end_offset, end;
 863         int err = 0, ofs = 1;
 864         unsigned int ofs_in_node, last_ofs_in_node;
 865         blkcnt_t prealloc;
 866         struct extent_info ei = {0,0,0};
 867         block_t blkaddr;
 868
 869         if (!maxblocks)
 870                 return 0;
 871
 872         map->m_len = 0;
 873         map->m_flags = 0;
 874
 875         /* it only supports block size == page size */
 876         pgofs = (pgoff_t)map->m_lblk;
 877         end = pgofs + maxblocks;
 878
 879         if (!create && f2fs_lookup_extent_cache(inode, pgofs, &ei)) {
 880                 map->m_pblk = ei.blk + pgofs - ei.fofs;
 881                 map->m_len = min((pgoff_t)maxblocks, ei.fofs + ei.len - pgofs);
 882                 map->m_flags = F2FS_MAP_MAPPED;
 883                 goto out;
 884         }
 885
 886 next_dnode:
 887         if (create)
 888                 __do_map_lock(sbi, flag, true);
 889
 890         /* When reading holes, we need its node page */
 891         set_new_dnode(&dn, inode, NULL, NULL, 0);
 892         err = get_dnode_of_data(&dn, pgofs, mode);
 893         if (err) {
 894                 if (flag == F2FS_GET_BLOCK_BMAP)
 895                         map->m_pblk = 0;
 896                 if (err == -ENOENT) {
 897                         err = 0;
 898                         if (map->m_next_pgofs)
 899                                 *map->m_next_pgofs =
 900                                         get_next_page_offset(&dn, pgofs);
 901                 }
 902                 goto unlock_out;
 903         }
 904
 905         prealloc = 0;
 906         last_ofs_in_node = ofs_in_node = dn.ofs_in_node;
 907         end_offset = ADDRS_PER_PAGE(dn.node_page, inode);
 908
 909 next_block:
 910         blkaddr = datablock_addr(dn.inode, dn.node_page, dn.ofs_in_node);
 911
 912         if (blkaddr == NEW_ADDR || blkaddr == NULL_ADDR) {
 913                 if (create) {
 914                         if (unlikely(f2fs_cp_error(sbi))) {
 915                                 err = -EIO;
 916                                 goto sync_out;
 917                         }
 918                         if (flag == F2FS_GET_BLOCK_PRE_AIO) {
 919                                 if (blkaddr == NULL_ADDR) {
 920                                         prealloc++;
 921                                         last_ofs_in_node = dn.ofs_in_node;
 922                                 }
 923                         } else {
 924                                 err = __allocate_data_block(&dn);
 925                                 if (!err)
 926                                         set_inode_flag(inode, FI_APPEND_WRITE);
 927                         }
 928                         if (err)
 929                                 goto sync_out;
 930                         map->m_flags |= F2FS_MAP_NEW;
 931                         blkaddr = dn.data_blkaddr;
 932                 } else {
 933                         if (flag == F2FS_GET_BLOCK_BMAP) {
 934                                 map->m_pblk = 0;
 935                                 goto sync_out;
 936                         }
 937                         if (flag == F2FS_GET_BLOCK_FIEMAP &&
 938                                                 blkaddr == NULL_ADDR) {
 939                                 if (map->m_next_pgofs)
 940                                         *map->m_next_pgofs = pgofs + 1;
 941                         }
 942                         if (flag != F2FS_GET_BLOCK_FIEMAP ||
 943                                                 blkaddr != NEW_ADDR)
 944                                 goto sync_out;
 945                 }
 946         }
 947
 948         if (flag == F2FS_GET_BLOCK_PRE_AIO)
 949                 goto skip;
 950
 951         if (map->m_len == 0) {
 952                 /* preallocated unwritten block should be mapped for fiemap. */
 953                 if (blkaddr == NEW_ADDR)
 954                         map->m_flags |= F2FS_MAP_UNWRITTEN;
 955                 map->m_flags |= F2FS_MAP_MAPPED;
 956
 957                 map->m_pblk = blkaddr;
 958                 map->m_len = 1;
 959         } else if ((map->m_pblk != NEW_ADDR &&
 960                         blkaddr == (map->m_pblk + ofs)) ||
 961                         (map->m_pblk == NEW_ADDR && blkaddr == NEW_ADDR) ||
 962                         flag == F2FS_GET_BLOCK_PRE_DIO) {
 963                 ofs++;
 964                 map->m_len++;
 965         } else {
 966                 goto sync_out;
 967         }
 968
 969 skip:
 970         dn.ofs_in_node++;
 971         pgofs++;
 972
 973         /* preallocate blocks in batch for one dnode page */
 974         if (flag == F2FS_GET_BLOCK_PRE_AIO &&
 975                         (pgofs == end || dn.ofs_in_node == end_offset)) {
 976
 977                 dn.ofs_in_node = ofs_in_node;
 978                 err = reserve_new_blocks(&dn, prealloc);
 979                 if (err)
 980                         goto sync_out;
 981
 982                 map->m_len += dn.ofs_in_node - ofs_in_node;
 983                 if (prealloc && dn.ofs_in_node != last_ofs_in_node + 1) {
 984                         err = -ENOSPC;
 985                         goto sync_out;
 986                 }
 987                 dn.ofs_in_node = end_offset;
 988         }
 989
 990         if (pgofs >= end)
 991                 goto sync_out;
 992         else if (dn.ofs_in_node < end_offset)
 993                 goto next_block;
 994
 995         f2fs_put_dnode(&dn);
 996
 997         if (create) {
 998                 __do_map_lock(sbi, flag, false);
 999                 f2fs_balance_fs(sbi, dn.node_changed);
1000         }
1001         goto next_dnode;
1002
1003 sync_out:
1004         f2fs_put_dnode(&dn);
1005 unlock_out:
1006         if (create) {
1007                 __do_map_lock(sbi, flag, false);
1008                 f2fs_balance_fs(sbi, dn.node_changed);
1009         }
1010 out:
1011         trace_f2fs_map_blocks(inode, map, err);
1012         return err;
1013 }
1014
1015 static int __get_data_block(struct inode *inode, sector_t iblock,
1016                         struct buffer_head *bh, int create, int flag,
1017                         pgoff_t *next_pgofs)
1018 {
1019         struct f2fs_map_blocks map;
1020         int err;
1021
1022         map.m_lblk = iblock;
1023         map.m_len = bh->b_size >> inode->i_blkbits;
1024         map.m_next_pgofs = next_pgofs;
1025
1026         err = f2fs_map_blocks(inode, &map, create, flag);
1027         if (!err) {
1028                 map_bh(bh, inode->i_sb, map.m_pblk);
1029                 bh->b_state = (bh->b_state & ~F2FS_MAP_FLAGS) | map.m_flags;
1030                 bh->b_size = (u64)map.m_len << inode->i_blkbits;
1031         }
1032         return err;
1033 }
1034
1035 static int get_data_block(struct inode *inode, sector_t iblock,
1036                         struct buffer_head *bh_result, int create, int flag,
1037                         pgoff_t *next_pgofs)
1038 {
1039         return __get_data_block(inode, iblock, bh_result, create,
1040                                                         flag, next_pgofs);
1041 }
1042
1043 static int get_data_block_dio(struct inode *inode, sector_t iblock,
1044                         struct buffer_head *bh_result, int create)
1045 {
1046         return __get_data_block(inode, iblock, bh_result, create,
1047                                                 F2FS_GET_BLOCK_DEFAULT, NULL);
1048 }
1049
1050 static int get_data_block_bmap(struct inode *inode, sector_t iblock,
1051                         struct buffer_head *bh_result, int create)
1052 {
1053         /* Block number less than F2FS MAX BLOCKS */
1054         if (unlikely(iblock >= F2FS_I_SB(inode)->max_file_blocks))
1055                 return -EFBIG;
1056
1057         return __get_data_block(inode, iblock, bh_result, create,
1058                                                 F2FS_GET_BLOCK_BMAP, NULL);
1059 }
1060
1061 static inline sector_t logical_to_blk(struct inode *inode, loff_t offset)
1062 {
1063         return (offset >> inode->i_blkbits);
1064 }
1065
1066 static inline loff_t blk_to_logical(struct inode *inode, sector_t blk)
1067 {
1068         return (blk << inode->i_blkbits);
1069 }
1070
1071 int f2fs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
1072                 u64 start, u64 len)
1073 {
1074         struct buffer_head map_bh;
1075         sector_t start_blk, last_blk;
1076         pgoff_t next_pgofs;
1077         u64 logical = 0, phys = 0, size = 0;
1078         u32 flags = 0;
1079         int ret = 0;
1080
1081         ret = fiemap_check_flags(fieinfo, FIEMAP_FLAG_SYNC);
1082         if (ret)
1083                 return ret;
1084
1085         if (f2fs_has_inline_data(inode)) {
1086                 ret = f2fs_inline_data_fiemap(inode, fieinfo, start, len);
1087                 if (ret != -EAGAIN)
1088                         return ret;
1089         }
1090
1091         inode_lock(inode);
1092
1093         if (logical_to_blk(inode, len) == 0)
1094                 len = blk_to_logical(inode, 1);
1095
1096         start_blk = logical_to_blk(inode, start);
1097         last_blk = logical_to_blk(inode, start + len - 1);
1098
1099 next:
1100         memset(&map_bh, 0, sizeof(struct buffer_head));
1101         map_bh.b_size = len;
1102
1103         ret = get_data_block(inode, start_blk, &map_bh, 0,
1104                                         F2FS_GET_BLOCK_FIEMAP, &next_pgofs);
1105         if (ret)
1106                 goto out;
1107
1108         /* HOLE */
1109         if (!buffer_mapped(&map_bh)) {
1110                 start_blk = next_pgofs;
1111
1112                 if (blk_to_logical(inode, start_blk) < blk_to_logical(inode,
1113                                         F2FS_I_SB(inode)->max_file_blocks))
1114                         goto prep_next;
1115
1116                 flags |= FIEMAP_EXTENT_LAST;
1117         }
1118
1119         if (size) {
1120                 if (f2fs_encrypted_inode(inode))
1121                         flags |= FIEMAP_EXTENT_DATA_ENCRYPTED;
1122
1123                 ret = fiemap_fill_next_extent(fieinfo, logical,
1124                                 phys, size, flags);
1125         }
1126
1127         if (start_blk > last_blk || ret)
1128                 goto out;
1129
1130         logical = blk_to_logical(inode, start_blk);
1131         phys = blk_to_logical(inode, map_bh.b_blocknr);
1132         size = map_bh.b_size;
1133         flags = 0;
1134         if (buffer_unwritten(&map_bh))
1135                 flags = FIEMAP_EXTENT_UNWRITTEN;
1136
1137         start_blk += logical_to_blk(inode, size);
1138
1139 prep_next:
1140         cond_resched();
1141         if (fatal_signal_pending(current))
1142                 ret = -EINTR;
1143         else
1144                 goto next;
1145 out:
1146         if (ret == 1)
1147                 ret = 0;
1148
1149         inode_unlock(inode);
1150         return ret;
1151 }
1152
1153 static struct bio *f2fs_grab_bio(struct inode *inode, block_t blkaddr,
1154                                  unsigned nr_pages)
1155 {
1156         struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
1157         struct fscrypt_ctx *ctx = NULL;
1158         struct bio *bio;
1159
1160         if (f2fs_encrypted_file(inode)) {
1161                 ctx = fscrypt_get_ctx(inode, GFP_NOFS);
1162                 if (IS_ERR(ctx))
1163                         return ERR_CAST(ctx);
1164
1165                 /* wait the page to be moved by cleaning */
1166                 f2fs_wait_on_block_writeback(sbi, blkaddr);
1167         }
1168
1169         bio = bio_alloc(GFP_KERNEL, min_t(int, nr_pages, BIO_MAX_PAGES));
1170         if (!bio) {
1171                 if (ctx)
1172                         fscrypt_release_ctx(ctx);
1173                 return ERR_PTR(-ENOMEM);
1174         }
1175         f2fs_target_device(sbi, blkaddr, bio);
1176         bio->bi_end_io = f2fs_read_end_io;
1177         bio->bi_private = ctx;
1178
1179         return bio;
1180 }
1181
1182 /*
1183  * This function was originally taken from fs/mpage.c, and customized for f2fs.
1184  * Major change was from block_size == page_size in f2fs by default.
1185  */
1186 static int f2fs_mpage_readpages(struct address_space *mapping,
1187                         struct list_head *pages, struct page *page,
1188                         unsigned nr_pages)
1189 {
1190         struct bio *bio = NULL;
1191         unsigned page_idx;
1192         sector_t last_block_in_bio = 0;
1193         struct inode *inode = mapping->host;
1194         const unsigned blkbits = inode->i_blkbits;
1195         const unsigned blocksize = 1 << blkbits;
1196         sector_t block_in_file;
1197         sector_t last_block;
1198         sector_t last_block_in_file;
1199         sector_t block_nr;
1200         struct f2fs_map_blocks map;
1201
1202         map.m_pblk = 0;
1203         map.m_lblk = 0;
1204         map.m_len = 0;
1205         map.m_flags = 0;
1206         map.m_next_pgofs = NULL;
1207
1208         for (page_idx = 0; nr_pages; page_idx++, nr_pages--) {
1209
1210                 if (pages) {
1211                         page = list_last_entry(pages, struct page, lru);
1212
1213                         prefetchw(&page->flags);
1214                         list_del(&page->lru);
1215                         if (add_to_page_cache_lru(page, mapping,
1216                                                   page->index,
1217                                                   readahead_gfp_mask(mapping)))
1218                                 goto next_page;
1219                 }
1220
1221                 block_in_file = (sector_t)page->index;
1222                 last_block = block_in_file + nr_pages;
1223                 last_block_in_file = (i_size_read(inode) + blocksize - 1) >>
1224                                                                 blkbits;
1225                 if (last_block > last_block_in_file)
1226                         last_block = last_block_in_file;
1227
1228                 /*
1229                  * Map blocks using the previous result first.
1230                  */
1231                 if ((map.m_flags & F2FS_MAP_MAPPED) &&
1232                                 block_in_file > map.m_lblk &&
1233                                 block_in_file < (map.m_lblk + map.m_len))
1234                         goto got_it;
1235
1236                 /*
1237                  * Then do more f2fs_map_blocks() calls until we are
1238                  * done with this page.
1239                  */
1240                 map.m_flags = 0;
1241
1242                 if (block_in_file < last_block) {
1243                         map.m_lblk = block_in_file;
1244                         map.m_len = last_block - block_in_file;
1245
1246                         if (f2fs_map_blocks(inode, &map, 0,
1247                                                 F2FS_GET_BLOCK_DEFAULT))
1248                                 goto set_error_page;
1249                 }
1250 got_it:
1251                 if ((map.m_flags & F2FS_MAP_MAPPED)) {
1252                         block_nr = map.m_pblk + block_in_file - map.m_lblk;
1253                         SetPageMappedToDisk(page);
1254
1255                         if (!PageUptodate(page) && !cleancache_get_page(page)) {
1256                                 SetPageUptodate(page);
1257                                 goto confused;
1258                         }
1259                 } else {
1260                         zero_user_segment(page, 0, PAGE_SIZE);
1261                         if (!PageUptodate(page))
1262                                 SetPageUptodate(page);
1263                         unlock_page(page);
1264                         goto next_page;
1265                 }
1266
1267                 /*
1268                  * This page will go to BIO.  Do we need to send this
1269                  * BIO off first?
1270                  */
1271                 if (bio && (last_block_in_bio != block_nr - 1 ||
1272                         !__same_bdev(F2FS_I_SB(inode), block_nr, bio))) {
1273 submit_and_realloc:
1274                         __submit_bio(F2FS_I_SB(inode), bio, DATA);
1275                         bio = NULL;
1276                 }
1277                 if (bio == NULL) {
1278                         bio = f2fs_grab_bio(inode, block_nr, nr_pages);
1279                         if (IS_ERR(bio)) {
1280                                 bio = NULL;
1281                                 goto set_error_page;
1282                         }
1283                         bio_set_op_attrs(bio, REQ_OP_READ, 0);
1284                 }
1285
1286                 if (bio_add_page(bio, page, blocksize, 0) < blocksize)
1287                         goto submit_and_realloc;
1288
1289                 last_block_in_bio = block_nr;
1290                 goto next_page;
1291 set_error_page:
1292                 SetPageError(page);
1293                 zero_user_segment(page, 0, PAGE_SIZE);
1294                 unlock_page(page);
1295                 goto next_page;
1296 confused:
1297                 if (bio) {
1298                         __submit_bio(F2FS_I_SB(inode), bio, DATA);
1299                         bio = NULL;
1300                 }
1301                 unlock_page(page);
1302 next_page:
1303                 if (pages)
1304                         put_page(page);
1305         }
1306         BUG_ON(pages && !list_empty(pages));
1307         if (bio)
1308                 __submit_bio(F2FS_I_SB(inode), bio, DATA);
1309         return 0;
1310 }
1311
1312 static int f2fs_read_data_page(struct file *file, struct page *page)
1313 {
1314         struct inode *inode = page->mapping->host;
1315         int ret = -EAGAIN;
1316
1317         trace_f2fs_readpage(page, DATA);
1318
1319         /* If the file has inline data, try to read it directly */
1320         if (f2fs_has_inline_data(inode))
1321                 ret = f2fs_read_inline_data(inode, page);
1322         if (ret == -EAGAIN)
1323                 ret = f2fs_mpage_readpages(page->mapping, NULL, page, 1);
1324         return ret;
1325 }
1326
1327 static int f2fs_read_data_pages(struct file *file,
1328                         struct address_space *mapping,
1329                         struct list_head *pages, unsigned nr_pages)
1330 {
1331         struct inode *inode = file->f_mapping->host;
1332         struct page *page = list_last_entry(pages, struct page, lru);
1333
1334         trace_f2fs_readpages(inode, page, nr_pages);
1335
1336         /* If the file has inline data, skip readpages */
1337         if (f2fs_has_inline_data(inode))
1338                 return 0;
1339
1340         return f2fs_mpage_readpages(mapping, pages, NULL, nr_pages);
1341 }
1342
1343 static int encrypt_one_page(struct f2fs_io_info *fio)
1344 {
1345         struct inode *inode = fio->page->mapping->host;
1346         gfp_t gfp_flags = GFP_NOFS;
1347
1348         if (!f2fs_encrypted_file(inode))
1349                 return 0;
1350
1351         /* wait for GCed encrypted page writeback */
1352         f2fs_wait_on_block_writeback(fio->sbi, fio->old_blkaddr);
1353
1354 retry_encrypt:
1355         fio->encrypted_page = fscrypt_encrypt_page(inode, fio->page,
1356                         PAGE_SIZE, 0, fio->page->index, gfp_flags);
1357         if (!IS_ERR(fio->encrypted_page))
1358                 return 0;
1359
1360         /* flush pending IOs and wait for a while in the ENOMEM case */
1361         if (PTR_ERR(fio->encrypted_page) == -ENOMEM) {
1362                 f2fs_flush_merged_writes(fio->sbi);
1363                 congestion_wait(BLK_RW_ASYNC, HZ/50);
1364                 gfp_flags |= __GFP_NOFAIL;
1365                 goto retry_encrypt;
1366         }
1367         return PTR_ERR(fio->encrypted_page);
1368 }
1369
1370 static inline bool need_inplace_update(struct f2fs_io_info *fio)
1371 {
1372         struct inode *inode = fio->page->mapping->host;
1373
1374         if (S_ISDIR(inode->i_mode) || f2fs_is_atomic_file(inode))
1375                 return false;
1376         if (is_cold_data(fio->page))
1377                 return false;
1378         if (IS_ATOMIC_WRITTEN_PAGE(fio->page))
1379                 return false;
1380
1381         return need_inplace_update_policy(inode, fio);
1382 }
1383
1384 static inline bool valid_ipu_blkaddr(struct f2fs_io_info *fio)
1385 {
1386         if (fio->old_blkaddr == NEW_ADDR)
1387                 return false;
1388         if (fio->old_blkaddr == NULL_ADDR)
1389                 return false;
1390         return true;
1391 }
1392
1393 int do_write_data_page(struct f2fs_io_info *fio)
1394 {
1395         struct page *page = fio->page;
1396         struct inode *inode = page->mapping->host;
1397         struct dnode_of_data dn;
1398         struct extent_info ei = {0,0,0};
1399         bool ipu_force = false;
1400         int err = 0;
1401
1402         set_new_dnode(&dn, inode, NULL, NULL, 0);
1403         if (need_inplace_update(fio) &&
1404                         f2fs_lookup_extent_cache(inode, page->index, &ei)) {
1405                 fio->old_blkaddr = ei.blk + page->index - ei.fofs;
1406
1407                 if (valid_ipu_blkaddr(fio)) {
1408                         ipu_force = true;
1409                         fio->need_lock = LOCK_DONE;
1410                         goto got_it;
1411                 }
1412         }
1413
1414         /* Deadlock due to between page->lock and f2fs_lock_op */
1415         if (fio->need_lock == LOCK_REQ && !f2fs_trylock_op(fio->sbi))
1416                 return -EAGAIN;
1417
1418         err = get_dnode_of_data(&dn, page->index, LOOKUP_NODE);
1419         if (err)
1420                 goto out;
1421
1422         fio->old_blkaddr = dn.data_blkaddr;
1423
1424         /* This page is already truncated */
1425         if (fio->old_blkaddr == NULL_ADDR) {
1426                 ClearPageUptodate(page);
1427                 goto out_writepage;
1428         }
1429 got_it:
1430         /*
1431          * If current allocation needs SSR,
1432          * it had better in-place writes for updated data.
1433          */
1434         if (ipu_force || (valid_ipu_blkaddr(fio) && need_inplace_update(fio))) {
1435                 err = encrypt_one_page(fio);
1436                 if (err)
1437                         goto out_writepage;
1438
1439                 set_page_writeback(page);
1440                 f2fs_put_dnode(&dn);
1441                 if (fio->need_lock == LOCK_REQ)
1442                         f2fs_unlock_op(fio->sbi);
1443                 err = rewrite_data_page(fio);
1444                 trace_f2fs_do_write_data_page(fio->page, IPU);
1445                 set_inode_flag(inode, FI_UPDATE_WRITE);
1446                 return err;
1447         }
1448
1449         if (fio->need_lock == LOCK_RETRY) {
1450                 if (!f2fs_trylock_op(fio->sbi)) {
1451                         err = -EAGAIN;
1452                         goto out_writepage;
1453                 }
1454                 fio->need_lock = LOCK_REQ;
1455         }
1456
1457         err = encrypt_one_page(fio);
1458         if (err)
1459                 goto out_writepage;
1460
1461         set_page_writeback(page);
1462
1463         /* LFS mode write path */
1464         write_data_page(&dn, fio);
1465         trace_f2fs_do_write_data_page(page, OPU);
1466         set_inode_flag(inode, FI_APPEND_WRITE);
1467         if (page->index == 0)
1468                 set_inode_flag(inode, FI_FIRST_BLOCK_WRITTEN);
1469 out_writepage:
1470         f2fs_put_dnode(&dn);
1471 out:
1472         if (fio->need_lock == LOCK_REQ)
1473                 f2fs_unlock_op(fio->sbi);
1474         return err;
1475 }
1476
1477 static int __write_data_page(struct page *page, bool *submitted,
1478                                 struct writeback_control *wbc,
1479                                 enum iostat_type io_type)
1480 {
1481         struct inode *inode = page->mapping->host;
1482         struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
1483         loff_t i_size = i_size_read(inode);
1484         const pgoff_t end_index = ((unsigned long long) i_size)
1485                                                         >> PAGE_SHIFT;
1486         loff_t psize = (page->index + 1) << PAGE_SHIFT;
1487         unsigned offset = 0;
1488         bool need_balance_fs = false;
1489         int err = 0;
1490         struct f2fs_io_info fio = {
1491                 .sbi = sbi,
1492                 .type = DATA,
1493                 .op = REQ_OP_WRITE,
1494                 .op_flags = wbc_to_write_flags(wbc),
1495                 .old_blkaddr = NULL_ADDR,
1496                 .page = page,
1497                 .encrypted_page = NULL,
1498                 .submitted = false,
1499                 .need_lock = LOCK_RETRY,
1500                 .io_type = io_type,
1501         };
1502
1503         trace_f2fs_writepage(page, DATA);
1504
1505         if (unlikely(is_sbi_flag_set(sbi, SBI_POR_DOING)))
1506                 goto redirty_out;
1507
1508         if (page->index < end_index)
1509                 goto write;
1510
1511         /*
1512          * If the offset is out-of-range of file size,
1513          * this page does not have to be written to disk.
1514          */
1515         offset = i_size & (PAGE_SIZE - 1);
1516         if ((page->index >= end_index + 1) || !offset)
1517                 goto out;
1518
1519         zero_user_segment(page, offset, PAGE_SIZE);
1520 write:
1521         if (f2fs_is_drop_cache(inode))
1522                 goto out;
1523         /* we should not write 0'th page having journal header */
1524         if (f2fs_is_volatile_file(inode) && (!page->index ||
1525                         (!wbc->for_reclaim &&
1526                         available_free_memory(sbi, BASE_CHECK))))
1527                 goto redirty_out;
1528
1529         /* we should bypass data pages to proceed the kworkder jobs */
1530         if (unlikely(f2fs_cp_error(sbi))) {
1531                 mapping_set_error(page->mapping, -EIO);
1532                 goto out;
1533         }
1534
1535         /* Dentry blocks are controlled by checkpoint */
1536         if (S_ISDIR(inode->i_mode)) {
1537                 fio.need_lock = LOCK_DONE;
1538                 err = do_write_data_page(&fio);
1539                 goto done;
1540         }
1541
1542         if (!wbc->for_reclaim)
1543                 need_balance_fs = true;
1544         else if (has_not_enough_free_secs(sbi, 0, 0))
1545                 goto redirty_out;
1546         else
1547                 set_inode_flag(inode, FI_HOT_DATA);
1548
1549         err = -EAGAIN;
1550         if (f2fs_has_inline_data(inode)) {
1551                 err = f2fs_write_inline_data(inode, page);
1552                 if (!err)
1553                         goto out;
1554         }
1555
1556         if (err == -EAGAIN) {
1557                 err = do_write_data_page(&fio);
1558                 if (err == -EAGAIN) {
1559                         fio.need_lock = LOCK_REQ;
1560                         err = do_write_data_page(&fio);
1561                 }
1562         }
1563         if (F2FS_I(inode)->last_disk_size < psize)
1564                 F2FS_I(inode)->last_disk_size = psize;
1565
1566 done:
1567         if (err && err != -ENOENT)
1568                 goto redirty_out;
1569
1570 out:
1571         inode_dec_dirty_pages(inode);
1572         if (err)
1573                 ClearPageUptodate(page);
1574
1575         if (wbc->for_reclaim) {
1576                 f2fs_submit_merged_write_cond(sbi, inode, 0, page->index, DATA);
1577                 clear_inode_flag(inode, FI_HOT_DATA);
1578                 remove_dirty_inode(inode);
1579                 submitted = NULL;
1580         }
1581
1582         unlock_page(page);
1583         if (!S_ISDIR(inode->i_mode))
1584                 f2fs_balance_fs(sbi, need_balance_fs);
1585
1586         if (unlikely(f2fs_cp_error(sbi))) {
1587                 f2fs_submit_merged_write(sbi, DATA);
1588                 submitted = NULL;
1589         }
1590
1591         if (submitted)
1592                 *submitted = fio.submitted;
1593
1594         return 0;
1595
1596 redirty_out:
1597         redirty_page_for_writepage(wbc, page);
1598         if (!err)
1599                 return AOP_WRITEPAGE_ACTIVATE;
1600         unlock_page(page);
1601         return err;
1602 }
1603
1604 static int f2fs_write_data_page(struct page *page,
1605                                         struct writeback_control *wbc)
1606 {
1607         return __write_data_page(page, NULL, wbc, FS_DATA_IO);
1608 }
1609
1610 /*
1611  * This function was copied from write_cche_pages from mm/page-writeback.c.
1612  * The major change is making write step of cold data page separately from
1613  * warm/hot data page.
1614  */
1615 static int f2fs_write_cache_pages(struct address_space *mapping,
1616                                         struct writeback_control *wbc,
1617                                         enum iostat_type io_type)
1618 {
1619         int ret = 0;
1620         int done = 0;
1621         struct pagevec pvec;
1622         int nr_pages;
1623         pgoff_t uninitialized_var(writeback_index);
1624         pgoff_t index;
1625         pgoff_t end;            /* Inclusive */
1626         pgoff_t done_index;
1627         pgoff_t last_idx = ULONG_MAX;
1628         int cycled;
1629         int range_whole = 0;
1630         int tag;
1631
1632         pagevec_init(&pvec, 0);
1633
1634         if (get_dirty_pages(mapping->host) <=
1635                                 SM_I(F2FS_M_SB(mapping))->min_hot_blocks)
1636                 set_inode_flag(mapping->host, FI_HOT_DATA);
1637         else
1638                 clear_inode_flag(mapping->host, FI_HOT_DATA);
1639
1640         if (wbc->range_cyclic) {
1641                 writeback_index = mapping->writeback_index; /* prev offset */
1642                 index = writeback_index;
1643                 if (index == 0)
1644                         cycled = 1;
1645                 else
1646                         cycled = 0;
1647                 end = -1;
1648         } else {
1649                 index = wbc->range_start >> PAGE_SHIFT;
1650                 end = wbc->range_end >> PAGE_SHIFT;
1651                 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
1652                         range_whole = 1;
1653                 cycled = 1; /* ignore range_cyclic tests */
1654         }
1655         if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)
1656                 tag = PAGECACHE_TAG_TOWRITE;
1657         else
1658                 tag = PAGECACHE_TAG_DIRTY;
1659 retry:
1660         if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)
1661                 tag_pages_for_writeback(mapping, index, end);
1662         done_index = index;
1663         while (!done && (index <= end)) {
1664                 int i;
1665
1666                 nr_pages = pagevec_lookup_tag(&pvec, mapping, &index, tag,
1667                               min(end - index, (pgoff_t)PAGEVEC_SIZE - 1) + 1);
1668                 if (nr_pages == 0)
1669                         break;
1670
1671                 for (i = 0; i < nr_pages; i++) {
1672                         struct page *page = pvec.pages[i];
1673                         bool submitted = false;
1674
1675                         if (page->index > end) {
1676                                 done = 1;
1677                                 break;
1678                         }
1679
1680                         done_index = page->index;
1681 retry_write:
1682                         lock_page(page);
1683
1684                         if (unlikely(page->mapping != mapping)) {
1685 continue_unlock:
1686                                 unlock_page(page);
1687                                 continue;
1688                         }
1689
1690                         if (!PageDirty(page)) {
1691                                 /* someone wrote it for us */
1692                                 goto continue_unlock;
1693                         }
1694
1695                         if (PageWriteback(page)) {
1696                                 if (wbc->sync_mode != WB_SYNC_NONE)
1697                                         f2fs_wait_on_page_writeback(page,
1698                                                                 DATA, true);
1699                                 else
1700                                         goto continue_unlock;
1701                         }
1702
1703                         BUG_ON(PageWriteback(page));
1704                         if (!clear_page_dirty_for_io(page))
1705                                 goto continue_unlock;
1706
1707                         ret = __write_data_page(page, &submitted, wbc, io_type);
1708                         if (unlikely(ret)) {
1709                                 /*
1710                                  * keep nr_to_write, since vfs uses this to
1711                                  * get # of written pages.
1712                                  */
1713                                 if (ret == AOP_WRITEPAGE_ACTIVATE) {
1714                                         unlock_page(page);
1715                                         ret = 0;
1716                                         continue;
1717                                 } else if (ret == -EAGAIN) {
1718                                         ret = 0;
1719                                         if (wbc->sync_mode == WB_SYNC_ALL) {
1720                                                 cond_resched();
1721                                                 congestion_wait(BLK_RW_ASYNC,
1722                                                                         HZ/50);
1723                                                 goto retry_write;
1724                                         }
1725                                         continue;
1726                                 }
1727                                 done_index = page->index + 1;
1728                                 done = 1;
1729                                 break;
1730                         } else if (submitted) {
1731                                 last_idx = page->index;
1732                         }
1733
1734                         /* give a priority to WB_SYNC threads */
1735                         if ((atomic_read(&F2FS_M_SB(mapping)->wb_sync_req) ||
1736                                         --wbc->nr_to_write <= 0) &&
1737                                         wbc->sync_mode == WB_SYNC_NONE) {
1738                                 done = 1;
1739                                 break;
1740                         }
1741                 }
1742                 pagevec_release(&pvec);
1743                 cond_resched();
1744         }
1745
1746         if (!cycled && !done) {
1747                 cycled = 1;
1748                 index = 0;
1749                 end = writeback_index - 1;
1750                 goto retry;
1751         }
1752         if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
1753                 mapping->writeback_index = done_index;
1754
1755         if (last_idx != ULONG_MAX)
1756                 f2fs_submit_merged_write_cond(F2FS_M_SB(mapping), mapping->host,
1757                                                 0, last_idx, DATA);
1758
1759         return ret;
1760 }
1761
1762 int __f2fs_write_data_pages(struct address_space *mapping,
1763                                                 struct writeback_control *wbc,
1764                                                 enum iostat_type io_type)
1765 {
1766         struct inode *inode = mapping->host;
1767         struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
1768         struct blk_plug plug;
1769         int ret;
1770
1771         /* deal with chardevs and other special file */
1772         if (!mapping->a_ops->writepage)
1773                 return 0;
1774
1775         /* skip writing if there is no dirty page in this inode */
1776         if (!get_dirty_pages(inode) && wbc->sync_mode == WB_SYNC_NONE)
1777                 return 0;
1778
1779         /* during POR, we don't need to trigger writepage at all. */
1780         if (unlikely(is_sbi_flag_set(sbi, SBI_POR_DOING)))
1781                 goto skip_write;
1782
1783         if (S_ISDIR(inode->i_mode) && wbc->sync_mode == WB_SYNC_NONE &&
1784                         get_dirty_pages(inode) < nr_pages_to_skip(sbi, DATA) &&
1785                         available_free_memory(sbi, DIRTY_DENTS))
1786                 goto skip_write;
1787
1788         /* skip writing during file defragment */
1789         if (is_inode_flag_set(inode, FI_DO_DEFRAG))
1790                 goto skip_write;
1791
1792         trace_f2fs_writepages(mapping->host, wbc, DATA);
1793
1794         /* to avoid spliting IOs due to mixed WB_SYNC_ALL and WB_SYNC_NONE */
1795         if (wbc->sync_mode == WB_SYNC_ALL)
1796                 atomic_inc(&sbi->wb_sync_req);
1797         else if (atomic_read(&sbi->wb_sync_req))
1798                 goto skip_write;
1799
1800         blk_start_plug(&plug);
1801         ret = f2fs_write_cache_pages(mapping, wbc, io_type);
1802         blk_finish_plug(&plug);
1803
1804         if (wbc->sync_mode == WB_SYNC_ALL)
1805                 atomic_dec(&sbi->wb_sync_req);
1806         /*
1807          * if some pages were truncated, we cannot guarantee its mapping->host
1808          * to detect pending bios.
1809          */
1810
1811         remove_dirty_inode(inode);
1812         return ret;
1813
1814 skip_write:
1815         wbc->pages_skipped += get_dirty_pages(inode);
1816         trace_f2fs_writepages(mapping->host, wbc, DATA);
1817         return 0;
1818 }
1819
1820 static int f2fs_write_data_pages(struct address_space *mapping,
1821                             struct writeback_control *wbc)
1822 {
1823         struct inode *inode = mapping->host;
1824
1825         return __f2fs_write_data_pages(mapping, wbc,
1826                         F2FS_I(inode)->cp_task == current ?
1827                         FS_CP_DATA_IO : FS_DATA_IO);
1828 }
1829
1830 static void f2fs_write_failed(struct address_space *mapping, loff_t to)
1831 {
1832         struct inode *inode = mapping->host;
1833         loff_t i_size = i_size_read(inode);
1834
1835         if (to > i_size) {
1836                 down_write(&F2FS_I(inode)->i_mmap_sem);
1837                 truncate_pagecache(inode, i_size);
1838                 truncate_blocks(inode, i_size, true);
1839                 up_write(&F2FS_I(inode)->i_mmap_sem);
1840         }
1841 }
1842
1843 static int prepare_write_begin(struct f2fs_sb_info *sbi,
1844                         struct page *page, loff_t pos, unsigned len,
1845                         block_t *blk_addr, bool *node_changed)
1846 {
1847         struct inode *inode = page->mapping->host;
1848         pgoff_t index = page->index;
1849         struct dnode_of_data dn;
1850         struct page *ipage;
1851         bool locked = false;
1852         struct extent_info ei = {0,0,0};
1853         int err = 0;
1854
1855         /*
1856          * we already allocated all the blocks, so we don't need to get
1857          * the block addresses when there is no need to fill the page.
1858          */
1859         if (!f2fs_has_inline_data(inode) && len == PAGE_SIZE &&
1860                         !is_inode_flag_set(inode, FI_NO_PREALLOC))
1861                 return 0;
1862
1863         if (f2fs_has_inline_data(inode) ||
1864                         (pos & PAGE_MASK) >= i_size_read(inode)) {
1865                 __do_map_lock(sbi, F2FS_GET_BLOCK_PRE_AIO, true);
1866                 locked = true;
1867         }
1868 restart:
1869         /* check inline_data */
1870         ipage = get_node_page(sbi, inode->i_ino);
1871         if (IS_ERR(ipage)) {
1872                 err = PTR_ERR(ipage);
1873                 goto unlock_out;
1874         }
1875
1876         set_new_dnode(&dn, inode, ipage, ipage, 0);
1877
1878         if (f2fs_has_inline_data(inode)) {
1879                 if (pos + len <= MAX_INLINE_DATA(inode)) {
1880                         read_inline_data(page, ipage);
1881                         set_inode_flag(inode, FI_DATA_EXIST);
1882                         if (inode->i_nlink)
1883                                 set_inline_node(ipage);
1884                 } else {
1885                         err = f2fs_convert_inline_page(&dn, page);
1886                         if (err)
1887                                 goto out;
1888                         if (dn.data_blkaddr == NULL_ADDR)
1889                                 err = f2fs_get_block(&dn, index);
1890                 }
1891         } else if (locked) {
1892                 err = f2fs_get_block(&dn, index);
1893         } else {
1894                 if (f2fs_lookup_extent_cache(inode, index, &ei)) {
1895                         dn.data_blkaddr = ei.blk + index - ei.fofs;
1896                 } else {
1897                         /* hole case */
1898                         err = get_dnode_of_data(&dn, index, LOOKUP_NODE);
1899                         if (err || dn.data_blkaddr == NULL_ADDR) {
1900                                 f2fs_put_dnode(&dn);
1901                                 __do_map_lock(sbi, F2FS_GET_BLOCK_PRE_AIO,
1902                                                                 true);
1903                                 locked = true;
1904                                 goto restart;
1905                         }
1906                 }
1907         }
1908
1909         /* convert_inline_page can make node_changed */
1910         *blk_addr = dn.data_blkaddr;
1911         *node_changed = dn.node_changed;
1912 out:
1913         f2fs_put_dnode(&dn);
1914 unlock_out:
1915         if (locked)
1916                 __do_map_lock(sbi, F2FS_GET_BLOCK_PRE_AIO, false);
1917         return err;
1918 }
1919
1920 static int f2fs_write_begin(struct file *file, struct address_space *mapping,
1921                 loff_t pos, unsigned len, unsigned flags,
1922                 struct page **pagep, void **fsdata)
1923 {
1924         struct inode *inode = mapping->host;
1925         struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
1926         struct page *page = NULL;
1927         pgoff_t index = ((unsigned long long) pos) >> PAGE_SHIFT;
1928         bool need_balance = false;
1929         block_t blkaddr = NULL_ADDR;
1930         int err = 0;
1931
1932         trace_f2fs_write_begin(inode, pos, len, flags);
1933
1934         /*
1935          * We should check this at this moment to avoid deadlock on inode page
1936          * and #0 page. The locking rule for inline_data conversion should be:
1937          * lock_page(page #0) -> lock_page(inode_page)
1938          */
1939         if (index != 0) {
1940                 err = f2fs_convert_inline_inode(inode);
1941                 if (err)
1942                         goto fail;
1943         }
1944 repeat:
1945         /*
1946          * Do not use grab_cache_page_write_begin() to avoid deadlock due to
1947          * wait_for_stable_page. Will wait that below with our IO control.
1948          */
1949         page = pagecache_get_page(mapping, index,
1950                                 FGP_LOCK | FGP_WRITE | FGP_CREAT, GFP_NOFS);
1951         if (!page) {
1952                 err = -ENOMEM;
1953                 goto fail;
1954         }
1955
1956         *pagep = page;
1957
1958         err = prepare_write_begin(sbi, page, pos, len,
1959                                         &blkaddr, &need_balance);
1960         if (err)
1961                 goto fail;
1962
1963         if (need_balance && has_not_enough_free_secs(sbi, 0, 0)) {
1964                 unlock_page(page);
1965                 f2fs_balance_fs(sbi, true);
1966                 lock_page(page);
1967                 if (page->mapping != mapping) {
1968                         /* The page got truncated from under us */
1969                         f2fs_put_page(page, 1);
1970                         goto repeat;
1971                 }
1972         }
1973
1974         f2fs_wait_on_page_writeback(page, DATA, false);
1975
1976         /* wait for GCed encrypted page writeback */
1977         if (f2fs_encrypted_file(inode))
1978                 f2fs_wait_on_block_writeback(sbi, blkaddr);
1979
1980         if (len == PAGE_SIZE || PageUptodate(page))
1981                 return 0;
1982
1983         if (!(pos & (PAGE_SIZE - 1)) && (pos + len) >= i_size_read(inode)) {
1984                 zero_user_segment(page, len, PAGE_SIZE);
1985                 return 0;
1986         }
1987
1988         if (blkaddr == NEW_ADDR) {
1989                 zero_user_segment(page, 0, PAGE_SIZE);
1990                 SetPageUptodate(page);
1991         } else {
1992                 struct bio *bio;
1993
1994                 bio = f2fs_grab_bio(inode, blkaddr, 1);
1995                 if (IS_ERR(bio)) {
1996                         err = PTR_ERR(bio);
1997                         goto fail;
1998                 }
1999                 bio->bi_opf = REQ_OP_READ;
2000                 if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE) {
2001                         bio_put(bio);
2002                         err = -EFAULT;
2003                         goto fail;
2004                 }
2005
2006                 __submit_bio(sbi, bio, DATA);
2007
2008                 lock_page(page);
2009                 if (unlikely(page->mapping != mapping)) {
2010                         f2fs_put_page(page, 1);
2011                         goto repeat;
2012                 }
2013                 if (unlikely(!PageUptodate(page))) {
2014                         err = -EIO;
2015                         goto fail;
2016                 }
2017         }
2018         return 0;
2019
2020 fail:
2021         f2fs_put_page(page, 1);
2022         f2fs_write_failed(mapping, pos + len);
2023         return err;
2024 }
2025
2026 static int f2fs_write_end(struct file *file,
2027                         struct address_space *mapping,
2028                         loff_t pos, unsigned len, unsigned copied,
2029                         struct page *page, void *fsdata)
2030 {
2031         struct inode *inode = page->mapping->host;
2032
2033         trace_f2fs_write_end(inode, pos, len, copied);
2034
2035         /*
2036          * This should be come from len == PAGE_SIZE, and we expect copied
2037          * should be PAGE_SIZE. Otherwise, we treat it with zero copied and
2038          * let generic_perform_write() try to copy data again through copied=0.
2039          */
2040         if (!PageUptodate(page)) {
2041                 if (unlikely(copied != len))
2042                         copied = 0;
2043                 else
2044                         SetPageUptodate(page);
2045         }
2046         if (!copied)
2047                 goto unlock_out;
2048
2049         set_page_dirty(page);
2050
2051         if (pos + copied > i_size_read(inode))
2052                 f2fs_i_size_write(inode, pos + copied);
2053 unlock_out:
2054         f2fs_put_page(page, 1);
2055         f2fs_update_time(F2FS_I_SB(inode), REQ_TIME);
2056         return copied;
2057 }
2058
2059 static int check_direct_IO(struct inode *inode, struct iov_iter *iter,
2060                            loff_t offset)
2061 {
2062         unsigned blocksize_mask = inode->i_sb->s_blocksize - 1;
2063
2064         if (offset & blocksize_mask)
2065                 return -EINVAL;
2066
2067         if (iov_iter_alignment(iter) & blocksize_mask)
2068                 return -EINVAL;
2069
2070         return 0;
2071 }
2072
2073 static ssize_t f2fs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
2074 {
2075         struct address_space *mapping = iocb->ki_filp->f_mapping;
2076         struct inode *inode = mapping->host;
2077         size_t count = iov_iter_count(iter);
2078         loff_t offset = iocb->ki_pos;
2079         int rw = iov_iter_rw(iter);
2080         int err;
2081
2082         err = check_direct_IO(inode, iter, offset);
2083         if (err)
2084                 return err;
2085
2086         if (__force_buffered_io(inode, rw))
2087                 return 0;
2088
2089         trace_f2fs_direct_IO_enter(inode, offset, count, rw);
2090
2091         down_read(&F2FS_I(inode)->dio_rwsem[rw]);
2092         err = blockdev_direct_IO(iocb, inode, iter, get_data_block_dio);
2093         up_read(&F2FS_I(inode)->dio_rwsem[rw]);
2094
2095         if (rw == WRITE) {
2096                 if (err > 0) {
2097                         f2fs_update_iostat(F2FS_I_SB(inode), APP_DIRECT_IO,
2098                                                                         err);
2099                         set_inode_flag(inode, FI_UPDATE_WRITE);
2100                 } else if (err < 0) {
2101                         f2fs_write_failed(mapping, offset + count);
2102                 }
2103         }
2104
2105         trace_f2fs_direct_IO_exit(inode, offset, count, rw, err);
2106
2107         return err;
2108 }
2109
2110 void f2fs_invalidate_page(struct page *page, unsigned int offset,
2111                                                         unsigned int length)
2112 {
2113         struct inode *inode = page->mapping->host;
2114         struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
2115
2116         if (inode->i_ino >= F2FS_ROOT_INO(sbi) &&
2117                 (offset % PAGE_SIZE || length != PAGE_SIZE))
2118                 return;
2119
2120         if (PageDirty(page)) {
2121                 if (inode->i_ino == F2FS_META_INO(sbi)) {
2122                         dec_page_count(sbi, F2FS_DIRTY_META);
2123                 } else if (inode->i_ino == F2FS_NODE_INO(sbi)) {
2124                         dec_page_count(sbi, F2FS_DIRTY_NODES);
2125                 } else {
2126                         inode_dec_dirty_pages(inode);
2127                         remove_dirty_inode(inode);
2128                 }
2129         }
2130
2131         /* This is atomic written page, keep Private */
2132         if (IS_ATOMIC_WRITTEN_PAGE(page))
2133                 return drop_inmem_page(inode, page);
2134
2135         set_page_private(page, 0);
2136         ClearPagePrivate(page);
2137 }
2138
2139 int f2fs_release_page(struct page *page, gfp_t wait)
2140 {
2141         /* If this is dirty page, keep PagePrivate */
2142         if (PageDirty(page))
2143                 return 0;
2144
2145         /* This is atomic written page, keep Private */
2146         if (IS_ATOMIC_WRITTEN_PAGE(page))
2147                 return 0;
2148
2149         set_page_private(page, 0);
2150         ClearPagePrivate(page);
2151         return 1;
2152 }
2153
2154 /*
2155  * This was copied from __set_page_dirty_buffers which gives higher performance
2156  * in very high speed storages. (e.g., pmem)
2157  */
2158 void f2fs_set_page_dirty_nobuffers(struct page *page)
2159 {
2160         struct address_space *mapping = page->mapping;
2161         unsigned long flags;
2162
2163         if (unlikely(!mapping))
2164                 return;
2165
2166         spin_lock(&mapping->private_lock);
2167         lock_page_memcg(page);
2168         SetPageDirty(page);
2169         spin_unlock(&mapping->private_lock);
2170
2171         spin_lock_irqsave(&mapping->tree_lock, flags);
2172         WARN_ON_ONCE(!PageUptodate(page));
2173         account_page_dirtied(page, mapping);
2174         radix_tree_tag_set(&mapping->page_tree,
2175                         page_index(page), PAGECACHE_TAG_DIRTY);
2176         spin_unlock_irqrestore(&mapping->tree_lock, flags);
2177         unlock_page_memcg(page);
2178
2179         __mark_inode_dirty(mapping->host, I_DIRTY_PAGES);
2180         return;
2181 }
2182
2183 static int f2fs_set_data_page_dirty(struct page *page)
2184 {
2185         struct address_space *mapping = page->mapping;
2186         struct inode *inode = mapping->host;
2187
2188         trace_f2fs_set_page_dirty(page, DATA);
2189
2190         if (!PageUptodate(page))
2191                 SetPageUptodate(page);
2192
2193         if (f2fs_is_atomic_file(inode) && !f2fs_is_commit_atomic_write(inode)) {
2194                 if (!IS_ATOMIC_WRITTEN_PAGE(page)) {
2195                         register_inmem_page(inode, page);
2196                         return 1;
2197                 }
2198                 /*
2199                  * Previously, this page has been registered, we just
2200                  * return here.
2201                  */
2202                 return 0;
2203         }
2204
2205         if (!PageDirty(page)) {
2206                 f2fs_set_page_dirty_nobuffers(page);
2207                 update_dirty_page(inode, page);
2208                 return 1;
2209         }
2210         return 0;
2211 }
2212
2213 static sector_t f2fs_bmap(struct address_space *mapping, sector_t block)
2214 {
2215         struct inode *inode = mapping->host;
2216
2217         if (f2fs_has_inline_data(inode))
2218                 return 0;
2219
2220         /* make sure allocating whole blocks */
2221         if (mapping_tagged(mapping, PAGECACHE_TAG_DIRTY))
2222                 filemap_write_and_wait(mapping);
2223
2224         return generic_block_bmap(mapping, block, get_data_block_bmap);
2225 }
2226
2227 #ifdef CONFIG_MIGRATION
2228 #include <linux/migrate.h>
2229
2230 int f2fs_migrate_page(struct address_space *mapping,
2231                 struct page *newpage, struct page *page, enum migrate_mode mode)
2232 {
2233         int rc, extra_count;
2234         struct f2fs_inode_info *fi = F2FS_I(mapping->host);
2235         bool atomic_written = IS_ATOMIC_WRITTEN_PAGE(page);
2236
2237         BUG_ON(PageWriteback(page));
2238
2239         /* migrating an atomic written page is safe with the inmem_lock hold */
2240         if (atomic_written) {
2241                 if (mode != MIGRATE_SYNC)
2242                         return -EBUSY;
2243                 if (!mutex_trylock(&fi->inmem_lock))
2244                         return -EAGAIN;
2245         }
2246
2247         /*
2248          * A reference is expected if PagePrivate set when move mapping,
2249          * however F2FS breaks this for maintaining dirty page counts when
2250          * truncating pages. So here adjusting the 'extra_count' make it work.
2251          */
2252         extra_count = (atomic_written ? 1 : 0) - page_has_private(page);
2253         rc = migrate_page_move_mapping(mapping, newpage,
2254                                 page, NULL, mode, extra_count);
2255         if (rc != MIGRATEPAGE_SUCCESS) {
2256                 if (atomic_written)
2257                         mutex_unlock(&fi->inmem_lock);
2258                 return rc;
2259         }
2260
2261         if (atomic_written) {
2262                 struct inmem_pages *cur;
2263                 list_for_each_entry(cur, &fi->inmem_pages, list)
2264                         if (cur->page == page) {
2265                                 cur->page = newpage;
2266                                 break;
2267                         }
2268                 mutex_unlock(&fi->inmem_lock);
2269                 put_page(page);
2270                 get_page(newpage);
2271         }
2272
2273         if (PagePrivate(page))
2274                 SetPagePrivate(newpage);
2275         set_page_private(newpage, page_private(page));
2276
2277         migrate_page_copy(newpage, page);
2278
2279         return MIGRATEPAGE_SUCCESS;
2280 }
2281 #endif
2282
2283 const struct address_space_operations f2fs_dblock_aops = {
2284         .readpage       = f2fs_read_data_page,
2285         .readpages      = f2fs_read_data_pages,
2286         .writepage      = f2fs_write_data_page,
2287         .writepages     = f2fs_write_data_pages,
2288         .write_begin    = f2fs_write_begin,
2289         .write_end      = f2fs_write_end,
2290         .set_page_dirty = f2fs_set_data_page_dirty,
2291         .invalidatepage = f2fs_invalidate_page,
2292         .releasepage    = f2fs_release_page,
2293         .direct_IO      = f2fs_direct_IO,
2294         .bmap           = f2fs_bmap,
2295 #ifdef CONFIG_MIGRATION
2296         .migratepage    = f2fs_migrate_page,
2297 #endif
2298 };