linux/fs/f2fs/data.c
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   1/*
   2 * fs/f2fs/data.c
   3 *
   4 * Copyright (c) 2012 Samsung Electronics Co., Ltd.
   5 *             http://www.samsung.com/
   6 *
   7 * This program is free software; you can redistribute it and/or modify
   8 * it under the terms of the GNU General Public License version 2 as
   9 * published by the Free Software Foundation.
  10 */
  11#include <linux/fs.h>
  12#include <linux/f2fs_fs.h>
  13#include <linux/buffer_head.h>
  14#include <linux/mpage.h>
  15#include <linux/writeback.h>
  16#include <linux/backing-dev.h>
  17#include <linux/pagevec.h>
  18#include <linux/blkdev.h>
  19#include <linux/bio.h>
  20#include <linux/prefetch.h>
  21#include <linux/uio.h>
  22#include <linux/cleancache.h>
  23
  24#include "f2fs.h"
  25#include "node.h"
  26#include "segment.h"
  27#include "trace.h"
  28#include <trace/events/f2fs.h>
  29
  30static void f2fs_read_end_io(struct bio *bio)
  31{
  32        struct bio_vec *bvec;
  33        int i;
  34
  35        if (f2fs_bio_encrypted(bio)) {
  36                if (bio->bi_error) {
  37                        fscrypt_release_ctx(bio->bi_private);
  38                } else {
  39                        fscrypt_decrypt_bio_pages(bio->bi_private, bio);
  40                        return;
  41                }
  42        }
  43
  44        bio_for_each_segment_all(bvec, bio, i) {
  45                struct page *page = bvec->bv_page;
  46
  47                if (!bio->bi_error) {
  48                        SetPageUptodate(page);
  49                } else {
  50                        ClearPageUptodate(page);
  51                        SetPageError(page);
  52                }
  53                unlock_page(page);
  54        }
  55        bio_put(bio);
  56}
  57
  58static void f2fs_write_end_io(struct bio *bio)
  59{
  60        struct f2fs_sb_info *sbi = bio->bi_private;
  61        struct bio_vec *bvec;
  62        int i;
  63
  64        bio_for_each_segment_all(bvec, bio, i) {
  65                struct page *page = bvec->bv_page;
  66
  67                fscrypt_pullback_bio_page(&page, true);
  68
  69                if (unlikely(bio->bi_error)) {
  70                        set_bit(AS_EIO, &page->mapping->flags);
  71                        f2fs_stop_checkpoint(sbi);
  72                }
  73                end_page_writeback(page);
  74                dec_page_count(sbi, F2FS_WRITEBACK);
  75        }
  76
  77        if (!get_pages(sbi, F2FS_WRITEBACK) && wq_has_sleeper(&sbi->cp_wait))
  78                wake_up(&sbi->cp_wait);
  79
  80        bio_put(bio);
  81}
  82
  83/*
  84 * Low-level block read/write IO operations.
  85 */
  86static struct bio *__bio_alloc(struct f2fs_sb_info *sbi, block_t blk_addr,
  87                                int npages, bool is_read)
  88{
  89        struct bio *bio;
  90
  91        bio = f2fs_bio_alloc(npages);
  92
  93        bio->bi_bdev = sbi->sb->s_bdev;
  94        bio->bi_iter.bi_sector = SECTOR_FROM_BLOCK(blk_addr);
  95        bio->bi_end_io = is_read ? f2fs_read_end_io : f2fs_write_end_io;
  96        bio->bi_private = is_read ? NULL : sbi;
  97
  98        return bio;
  99}
 100
 101static void __submit_merged_bio(struct f2fs_bio_info *io)
 102{
 103        struct f2fs_io_info *fio = &io->fio;
 104
 105        if (!io->bio)
 106                return;
 107
 108        if (is_read_io(fio->rw))
 109                trace_f2fs_submit_read_bio(io->sbi->sb, fio, io->bio);
 110        else
 111                trace_f2fs_submit_write_bio(io->sbi->sb, fio, io->bio);
 112
 113        submit_bio(fio->rw, io->bio);
 114        io->bio = NULL;
 115}
 116
 117static bool __has_merged_page(struct f2fs_bio_info *io, struct inode *inode,
 118                                                struct page *page, nid_t ino)
 119{
 120        struct bio_vec *bvec;
 121        struct page *target;
 122        int i;
 123
 124        if (!io->bio)
 125                return false;
 126
 127        if (!inode && !page && !ino)
 128                return true;
 129
 130        bio_for_each_segment_all(bvec, io->bio, i) {
 131
 132                if (bvec->bv_page->mapping)
 133                        target = bvec->bv_page;
 134                else
 135                        target = fscrypt_control_page(bvec->bv_page);
 136
 137                if (inode && inode == target->mapping->host)
 138                        return true;
 139                if (page && page == target)
 140                        return true;
 141                if (ino && ino == ino_of_node(target))
 142                        return true;
 143        }
 144
 145        return false;
 146}
 147
 148static bool has_merged_page(struct f2fs_sb_info *sbi, struct inode *inode,
 149                                                struct page *page, nid_t ino,
 150                                                enum page_type type)
 151{
 152        enum page_type btype = PAGE_TYPE_OF_BIO(type);
 153        struct f2fs_bio_info *io = &sbi->write_io[btype];
 154        bool ret;
 155
 156        down_read(&io->io_rwsem);
 157        ret = __has_merged_page(io, inode, page, ino);
 158        up_read(&io->io_rwsem);
 159        return ret;
 160}
 161
 162static void __f2fs_submit_merged_bio(struct f2fs_sb_info *sbi,
 163                                struct inode *inode, struct page *page,
 164                                nid_t ino, enum page_type type, int rw)
 165{
 166        enum page_type btype = PAGE_TYPE_OF_BIO(type);
 167        struct f2fs_bio_info *io;
 168
 169        io = is_read_io(rw) ? &sbi->read_io : &sbi->write_io[btype];
 170
 171        down_write(&io->io_rwsem);
 172
 173        if (!__has_merged_page(io, inode, page, ino))
 174                goto out;
 175
 176        /* change META to META_FLUSH in the checkpoint procedure */
 177        if (type >= META_FLUSH) {
 178                io->fio.type = META_FLUSH;
 179                if (test_opt(sbi, NOBARRIER))
 180                        io->fio.rw = WRITE_FLUSH | REQ_META | REQ_PRIO;
 181                else
 182                        io->fio.rw = WRITE_FLUSH_FUA | REQ_META | REQ_PRIO;
 183        }
 184        __submit_merged_bio(io);
 185out:
 186        up_write(&io->io_rwsem);
 187}
 188
 189void f2fs_submit_merged_bio(struct f2fs_sb_info *sbi, enum page_type type,
 190                                                                        int rw)
 191{
 192        __f2fs_submit_merged_bio(sbi, NULL, NULL, 0, type, rw);
 193}
 194
 195void f2fs_submit_merged_bio_cond(struct f2fs_sb_info *sbi,
 196                                struct inode *inode, struct page *page,
 197                                nid_t ino, enum page_type type, int rw)
 198{
 199        if (has_merged_page(sbi, inode, page, ino, type))
 200                __f2fs_submit_merged_bio(sbi, inode, page, ino, type, rw);
 201}
 202
 203void f2fs_flush_merged_bios(struct f2fs_sb_info *sbi)
 204{
 205        f2fs_submit_merged_bio(sbi, DATA, WRITE);
 206        f2fs_submit_merged_bio(sbi, NODE, WRITE);
 207        f2fs_submit_merged_bio(sbi, META, WRITE);
 208}
 209
 210/*
 211 * Fill the locked page with data located in the block address.
 212 * Return unlocked page.
 213 */
 214int f2fs_submit_page_bio(struct f2fs_io_info *fio)
 215{
 216        struct bio *bio;
 217        struct page *page = fio->encrypted_page ?
 218                        fio->encrypted_page : fio->page;
 219
 220        trace_f2fs_submit_page_bio(page, fio);
 221        f2fs_trace_ios(fio, 0);
 222
 223        /* Allocate a new bio */
 224        bio = __bio_alloc(fio->sbi, fio->new_blkaddr, 1, is_read_io(fio->rw));
 225
 226        if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE) {
 227                bio_put(bio);
 228                return -EFAULT;
 229        }
 230
 231        submit_bio(fio->rw, bio);
 232        return 0;
 233}
 234
 235void f2fs_submit_page_mbio(struct f2fs_io_info *fio)
 236{
 237        struct f2fs_sb_info *sbi = fio->sbi;
 238        enum page_type btype = PAGE_TYPE_OF_BIO(fio->type);
 239        struct f2fs_bio_info *io;
 240        bool is_read = is_read_io(fio->rw);
 241        struct page *bio_page;
 242
 243        io = is_read ? &sbi->read_io : &sbi->write_io[btype];
 244
 245        if (fio->old_blkaddr != NEW_ADDR)
 246                verify_block_addr(sbi, fio->old_blkaddr);
 247        verify_block_addr(sbi, fio->new_blkaddr);
 248
 249        down_write(&io->io_rwsem);
 250
 251        if (!is_read)
 252                inc_page_count(sbi, F2FS_WRITEBACK);
 253
 254        if (io->bio && (io->last_block_in_bio != fio->new_blkaddr - 1 ||
 255                                                io->fio.rw != fio->rw))
 256                __submit_merged_bio(io);
 257alloc_new:
 258        if (io->bio == NULL) {
 259                int bio_blocks = MAX_BIO_BLOCKS(sbi);
 260
 261                io->bio = __bio_alloc(sbi, fio->new_blkaddr,
 262                                                bio_blocks, is_read);
 263                io->fio = *fio;
 264        }
 265
 266        bio_page = fio->encrypted_page ? fio->encrypted_page : fio->page;
 267
 268        if (bio_add_page(io->bio, bio_page, PAGE_SIZE, 0) <
 269                                                        PAGE_SIZE) {
 270                __submit_merged_bio(io);
 271                goto alloc_new;
 272        }
 273
 274        io->last_block_in_bio = fio->new_blkaddr;
 275        f2fs_trace_ios(fio, 0);
 276
 277        up_write(&io->io_rwsem);
 278        trace_f2fs_submit_page_mbio(fio->page, fio);
 279}
 280
 281/*
 282 * Lock ordering for the change of data block address:
 283 * ->data_page
 284 *  ->node_page
 285 *    update block addresses in the node page
 286 */
 287void set_data_blkaddr(struct dnode_of_data *dn)
 288{
 289        struct f2fs_node *rn;
 290        __le32 *addr_array;
 291        struct page *node_page = dn->node_page;
 292        unsigned int ofs_in_node = dn->ofs_in_node;
 293
 294        f2fs_wait_on_page_writeback(node_page, NODE, true);
 295
 296        rn = F2FS_NODE(node_page);
 297
 298        /* Get physical address of data block */
 299        addr_array = blkaddr_in_node(rn);
 300        addr_array[ofs_in_node] = cpu_to_le32(dn->data_blkaddr);
 301        if (set_page_dirty(node_page))
 302                dn->node_changed = true;
 303}
 304
 305void f2fs_update_data_blkaddr(struct dnode_of_data *dn, block_t blkaddr)
 306{
 307        dn->data_blkaddr = blkaddr;
 308        set_data_blkaddr(dn);
 309        f2fs_update_extent_cache(dn);
 310}
 311
 312int reserve_new_block(struct dnode_of_data *dn)
 313{
 314        struct f2fs_sb_info *sbi = F2FS_I_SB(dn->inode);
 315
 316        if (unlikely(is_inode_flag_set(F2FS_I(dn->inode), FI_NO_ALLOC)))
 317                return -EPERM;
 318        if (unlikely(!inc_valid_block_count(sbi, dn->inode, 1)))
 319                return -ENOSPC;
 320
 321        trace_f2fs_reserve_new_block(dn->inode, dn->nid, dn->ofs_in_node);
 322
 323        dn->data_blkaddr = NEW_ADDR;
 324        set_data_blkaddr(dn);
 325        mark_inode_dirty(dn->inode);
 326        sync_inode_page(dn);
 327        return 0;
 328}
 329
 330int f2fs_reserve_block(struct dnode_of_data *dn, pgoff_t index)
 331{
 332        bool need_put = dn->inode_page ? false : true;
 333        int err;
 334
 335        err = get_dnode_of_data(dn, index, ALLOC_NODE);
 336        if (err)
 337                return err;
 338
 339        if (dn->data_blkaddr == NULL_ADDR)
 340                err = reserve_new_block(dn);
 341        if (err || need_put)
 342                f2fs_put_dnode(dn);
 343        return err;
 344}
 345
 346int f2fs_get_block(struct dnode_of_data *dn, pgoff_t index)
 347{
 348        struct extent_info ei;
 349        struct inode *inode = dn->inode;
 350
 351        if (f2fs_lookup_extent_cache(inode, index, &ei)) {
 352                dn->data_blkaddr = ei.blk + index - ei.fofs;
 353                return 0;
 354        }
 355
 356        return f2fs_reserve_block(dn, index);
 357}
 358
 359struct page *get_read_data_page(struct inode *inode, pgoff_t index,
 360                                                int rw, bool for_write)
 361{
 362        struct address_space *mapping = inode->i_mapping;
 363        struct dnode_of_data dn;
 364        struct page *page;
 365        struct extent_info ei;
 366        int err;
 367        struct f2fs_io_info fio = {
 368                .sbi = F2FS_I_SB(inode),
 369                .type = DATA,
 370                .rw = rw,
 371                .encrypted_page = NULL,
 372        };
 373
 374        if (f2fs_encrypted_inode(inode) && S_ISREG(inode->i_mode))
 375                return read_mapping_page(mapping, index, NULL);
 376
 377        page = f2fs_grab_cache_page(mapping, index, for_write);
 378        if (!page)
 379                return ERR_PTR(-ENOMEM);
 380
 381        if (f2fs_lookup_extent_cache(inode, index, &ei)) {
 382                dn.data_blkaddr = ei.blk + index - ei.fofs;
 383                goto got_it;
 384        }
 385
 386        set_new_dnode(&dn, inode, NULL, NULL, 0);
 387        err = get_dnode_of_data(&dn, index, LOOKUP_NODE);
 388        if (err)
 389                goto put_err;
 390        f2fs_put_dnode(&dn);
 391
 392        if (unlikely(dn.data_blkaddr == NULL_ADDR)) {
 393                err = -ENOENT;
 394                goto put_err;
 395        }
 396got_it:
 397        if (PageUptodate(page)) {
 398                unlock_page(page);
 399                return page;
 400        }
 401
 402        /*
 403         * A new dentry page is allocated but not able to be written, since its
 404         * new inode page couldn't be allocated due to -ENOSPC.
 405         * In such the case, its blkaddr can be remained as NEW_ADDR.
 406         * see, f2fs_add_link -> get_new_data_page -> init_inode_metadata.
 407         */
 408        if (dn.data_blkaddr == NEW_ADDR) {
 409                zero_user_segment(page, 0, PAGE_SIZE);
 410                SetPageUptodate(page);
 411                unlock_page(page);
 412                return page;
 413        }
 414
 415        fio.new_blkaddr = fio.old_blkaddr = dn.data_blkaddr;
 416        fio.page = page;
 417        err = f2fs_submit_page_bio(&fio);
 418        if (err)
 419                goto put_err;
 420        return page;
 421
 422put_err:
 423        f2fs_put_page(page, 1);
 424        return ERR_PTR(err);
 425}
 426
 427struct page *find_data_page(struct inode *inode, pgoff_t index)
 428{
 429        struct address_space *mapping = inode->i_mapping;
 430        struct page *page;
 431
 432        page = find_get_page(mapping, index);
 433        if (page && PageUptodate(page))
 434                return page;
 435        f2fs_put_page(page, 0);
 436
 437        page = get_read_data_page(inode, index, READ_SYNC, false);
 438        if (IS_ERR(page))
 439                return page;
 440
 441        if (PageUptodate(page))
 442                return page;
 443
 444        wait_on_page_locked(page);
 445        if (unlikely(!PageUptodate(page))) {
 446                f2fs_put_page(page, 0);
 447                return ERR_PTR(-EIO);
 448        }
 449        return page;
 450}
 451
 452/*
 453 * If it tries to access a hole, return an error.
 454 * Because, the callers, functions in dir.c and GC, should be able to know
 455 * whether this page exists or not.
 456 */
 457struct page *get_lock_data_page(struct inode *inode, pgoff_t index,
 458                                                        bool for_write)
 459{
 460        struct address_space *mapping = inode->i_mapping;
 461        struct page *page;
 462repeat:
 463        page = get_read_data_page(inode, index, READ_SYNC, for_write);
 464        if (IS_ERR(page))
 465                return page;
 466
 467        /* wait for read completion */
 468        lock_page(page);
 469        if (unlikely(!PageUptodate(page))) {
 470                f2fs_put_page(page, 1);
 471                return ERR_PTR(-EIO);
 472        }
 473        if (unlikely(page->mapping != mapping)) {
 474                f2fs_put_page(page, 1);
 475                goto repeat;
 476        }
 477        return page;
 478}
 479
 480/*
 481 * Caller ensures that this data page is never allocated.
 482 * A new zero-filled data page is allocated in the page cache.
 483 *
 484 * Also, caller should grab and release a rwsem by calling f2fs_lock_op() and
 485 * f2fs_unlock_op().
 486 * Note that, ipage is set only by make_empty_dir, and if any error occur,
 487 * ipage should be released by this function.
 488 */
 489struct page *get_new_data_page(struct inode *inode,
 490                struct page *ipage, pgoff_t index, bool new_i_size)
 491{
 492        struct address_space *mapping = inode->i_mapping;
 493        struct page *page;
 494        struct dnode_of_data dn;
 495        int err;
 496
 497        page = f2fs_grab_cache_page(mapping, index, true);
 498        if (!page) {
 499                /*
 500                 * before exiting, we should make sure ipage will be released
 501                 * if any error occur.
 502                 */
 503                f2fs_put_page(ipage, 1);
 504                return ERR_PTR(-ENOMEM);
 505        }
 506
 507        set_new_dnode(&dn, inode, ipage, NULL, 0);
 508        err = f2fs_reserve_block(&dn, index);
 509        if (err) {
 510                f2fs_put_page(page, 1);
 511                return ERR_PTR(err);
 512        }
 513        if (!ipage)
 514                f2fs_put_dnode(&dn);
 515
 516        if (PageUptodate(page))
 517                goto got_it;
 518
 519        if (dn.data_blkaddr == NEW_ADDR) {
 520                zero_user_segment(page, 0, PAGE_SIZE);
 521                SetPageUptodate(page);
 522        } else {
 523                f2fs_put_page(page, 1);
 524
 525                /* if ipage exists, blkaddr should be NEW_ADDR */
 526                f2fs_bug_on(F2FS_I_SB(inode), ipage);
 527                page = get_lock_data_page(inode, index, true);
 528                if (IS_ERR(page))
 529                        return page;
 530        }
 531got_it:
 532        if (new_i_size && i_size_read(inode) <
 533                                ((loff_t)(index + 1) << PAGE_SHIFT)) {
 534                i_size_write(inode, ((loff_t)(index + 1) << PAGE_SHIFT));
 535                /* Only the directory inode sets new_i_size */
 536                set_inode_flag(F2FS_I(inode), FI_UPDATE_DIR);
 537        }
 538        return page;
 539}
 540
 541static int __allocate_data_block(struct dnode_of_data *dn)
 542{
 543        struct f2fs_sb_info *sbi = F2FS_I_SB(dn->inode);
 544        struct f2fs_summary sum;
 545        struct node_info ni;
 546        int seg = CURSEG_WARM_DATA;
 547        pgoff_t fofs;
 548
 549        if (unlikely(is_inode_flag_set(F2FS_I(dn->inode), FI_NO_ALLOC)))
 550                return -EPERM;
 551
 552        dn->data_blkaddr = datablock_addr(dn->node_page, dn->ofs_in_node);
 553        if (dn->data_blkaddr == NEW_ADDR)
 554                goto alloc;
 555
 556        if (unlikely(!inc_valid_block_count(sbi, dn->inode, 1)))
 557                return -ENOSPC;
 558
 559alloc:
 560        get_node_info(sbi, dn->nid, &ni);
 561        set_summary(&sum, dn->nid, dn->ofs_in_node, ni.version);
 562
 563        if (dn->ofs_in_node == 0 && dn->inode_page == dn->node_page)
 564                seg = CURSEG_DIRECT_IO;
 565
 566        allocate_data_block(sbi, NULL, dn->data_blkaddr, &dn->data_blkaddr,
 567                                                                &sum, seg);
 568        set_data_blkaddr(dn);
 569
 570        /* update i_size */
 571        fofs = start_bidx_of_node(ofs_of_node(dn->node_page), dn->inode) +
 572                                                        dn->ofs_in_node;
 573        if (i_size_read(dn->inode) < ((loff_t)(fofs + 1) << PAGE_SHIFT))
 574                i_size_write(dn->inode,
 575                                ((loff_t)(fofs + 1) << PAGE_SHIFT));
 576        return 0;
 577}
 578
 579ssize_t f2fs_preallocate_blocks(struct kiocb *iocb, struct iov_iter *from)
 580{
 581        struct inode *inode = file_inode(iocb->ki_filp);
 582        struct f2fs_map_blocks map;
 583        ssize_t ret = 0;
 584
 585        map.m_lblk = F2FS_BYTES_TO_BLK(iocb->ki_pos);
 586        map.m_len = F2FS_BLK_ALIGN(iov_iter_count(from));
 587        map.m_next_pgofs = NULL;
 588
 589        if (f2fs_encrypted_inode(inode))
 590                return 0;
 591
 592        if (iocb->ki_flags & IOCB_DIRECT) {
 593                ret = f2fs_convert_inline_inode(inode);
 594                if (ret)
 595                        return ret;
 596                return f2fs_map_blocks(inode, &map, 1, F2FS_GET_BLOCK_PRE_DIO);
 597        }
 598        if (iocb->ki_pos + iov_iter_count(from) > MAX_INLINE_DATA) {
 599                ret = f2fs_convert_inline_inode(inode);
 600                if (ret)
 601                        return ret;
 602        }
 603        if (!f2fs_has_inline_data(inode))
 604                return f2fs_map_blocks(inode, &map, 1, F2FS_GET_BLOCK_PRE_AIO);
 605        return ret;
 606}
 607
 608/*
 609 * f2fs_map_blocks() now supported readahead/bmap/rw direct_IO with
 610 * f2fs_map_blocks structure.
 611 * If original data blocks are allocated, then give them to blockdev.
 612 * Otherwise,
 613 *     a. preallocate requested block addresses
 614 *     b. do not use extent cache for better performance
 615 *     c. give the block addresses to blockdev
 616 */
 617int f2fs_map_blocks(struct inode *inode, struct f2fs_map_blocks *map,
 618                                                int create, int flag)
 619{
 620        unsigned int maxblocks = map->m_len;
 621        struct dnode_of_data dn;
 622        struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
 623        int mode = create ? ALLOC_NODE : LOOKUP_NODE_RA;
 624        pgoff_t pgofs, end_offset;
 625        int err = 0, ofs = 1;
 626        struct extent_info ei;
 627        bool allocated = false;
 628        block_t blkaddr;
 629
 630        map->m_len = 0;
 631        map->m_flags = 0;
 632
 633        /* it only supports block size == page size */
 634        pgofs = (pgoff_t)map->m_lblk;
 635
 636        if (!create && f2fs_lookup_extent_cache(inode, pgofs, &ei)) {
 637                map->m_pblk = ei.blk + pgofs - ei.fofs;
 638                map->m_len = min((pgoff_t)maxblocks, ei.fofs + ei.len - pgofs);
 639                map->m_flags = F2FS_MAP_MAPPED;
 640                goto out;
 641        }
 642
 643next_dnode:
 644        if (create)
 645                f2fs_lock_op(sbi);
 646
 647        /* When reading holes, we need its node page */
 648        set_new_dnode(&dn, inode, NULL, NULL, 0);
 649        err = get_dnode_of_data(&dn, pgofs, mode);
 650        if (err) {
 651                if (err == -ENOENT) {
 652                        err = 0;
 653                        if (map->m_next_pgofs)
 654                                *map->m_next_pgofs =
 655                                        get_next_page_offset(&dn, pgofs);
 656                }
 657                goto unlock_out;
 658        }
 659
 660        end_offset = ADDRS_PER_PAGE(dn.node_page, inode);
 661
 662next_block:
 663        blkaddr = datablock_addr(dn.node_page, dn.ofs_in_node);
 664
 665        if (blkaddr == NEW_ADDR || blkaddr == NULL_ADDR) {
 666                if (create) {
 667                        if (unlikely(f2fs_cp_error(sbi))) {
 668                                err = -EIO;
 669                                goto sync_out;
 670                        }
 671                        if (flag == F2FS_GET_BLOCK_PRE_AIO) {
 672                                if (blkaddr == NULL_ADDR)
 673                                        err = reserve_new_block(&dn);
 674                        } else {
 675                                err = __allocate_data_block(&dn);
 676                        }
 677                        if (err)
 678                                goto sync_out;
 679                        allocated = true;
 680                        map->m_flags = F2FS_MAP_NEW;
 681                        blkaddr = dn.data_blkaddr;
 682                } else {
 683                        if (flag == F2FS_GET_BLOCK_FIEMAP &&
 684                                                blkaddr == NULL_ADDR) {
 685                                if (map->m_next_pgofs)
 686                                        *map->m_next_pgofs = pgofs + 1;
 687                        }
 688                        if (flag != F2FS_GET_BLOCK_FIEMAP ||
 689                                                blkaddr != NEW_ADDR) {
 690                                if (flag == F2FS_GET_BLOCK_BMAP)
 691                                        err = -ENOENT;
 692                                goto sync_out;
 693                        }
 694                }
 695        }
 696
 697        if (map->m_len == 0) {
 698                /* preallocated unwritten block should be mapped for fiemap. */
 699                if (blkaddr == NEW_ADDR)
 700                        map->m_flags |= F2FS_MAP_UNWRITTEN;
 701                map->m_flags |= F2FS_MAP_MAPPED;
 702
 703                map->m_pblk = blkaddr;
 704                map->m_len = 1;
 705        } else if ((map->m_pblk != NEW_ADDR &&
 706                        blkaddr == (map->m_pblk + ofs)) ||
 707                        (map->m_pblk == NEW_ADDR && blkaddr == NEW_ADDR) ||
 708                        flag == F2FS_GET_BLOCK_PRE_DIO ||
 709                        flag == F2FS_GET_BLOCK_PRE_AIO) {
 710                ofs++;
 711                map->m_len++;
 712        } else {
 713                goto sync_out;
 714        }
 715
 716        dn.ofs_in_node++;
 717        pgofs++;
 718
 719        if (map->m_len < maxblocks) {
 720                if (dn.ofs_in_node < end_offset)
 721                        goto next_block;
 722
 723                if (allocated)
 724                        sync_inode_page(&dn);
 725                f2fs_put_dnode(&dn);
 726
 727                if (create) {
 728                        f2fs_unlock_op(sbi);
 729                        f2fs_balance_fs(sbi, allocated);
 730                }
 731                allocated = false;
 732                goto next_dnode;
 733        }
 734
 735sync_out:
 736        if (allocated)
 737                sync_inode_page(&dn);
 738        f2fs_put_dnode(&dn);
 739unlock_out:
 740        if (create) {
 741                f2fs_unlock_op(sbi);
 742                f2fs_balance_fs(sbi, allocated);
 743        }
 744out:
 745        trace_f2fs_map_blocks(inode, map, err);
 746        return err;
 747}
 748
 749static int __get_data_block(struct inode *inode, sector_t iblock,
 750                        struct buffer_head *bh, int create, int flag,
 751                        pgoff_t *next_pgofs)
 752{
 753        struct f2fs_map_blocks map;
 754        int ret;
 755
 756        map.m_lblk = iblock;
 757        map.m_len = bh->b_size >> inode->i_blkbits;
 758        map.m_next_pgofs = next_pgofs;
 759
 760        ret = f2fs_map_blocks(inode, &map, create, flag);
 761        if (!ret) {
 762                map_bh(bh, inode->i_sb, map.m_pblk);
 763                bh->b_state = (bh->b_state & ~F2FS_MAP_FLAGS) | map.m_flags;
 764                bh->b_size = map.m_len << inode->i_blkbits;
 765        }
 766        return ret;
 767}
 768
 769static int get_data_block(struct inode *inode, sector_t iblock,
 770                        struct buffer_head *bh_result, int create, int flag,
 771                        pgoff_t *next_pgofs)
 772{
 773        return __get_data_block(inode, iblock, bh_result, create,
 774                                                        flag, next_pgofs);
 775}
 776
 777static int get_data_block_dio(struct inode *inode, sector_t iblock,
 778                        struct buffer_head *bh_result, int create)
 779{
 780        return __get_data_block(inode, iblock, bh_result, create,
 781                                                F2FS_GET_BLOCK_DIO, NULL);
 782}
 783
 784static int get_data_block_bmap(struct inode *inode, sector_t iblock,
 785                        struct buffer_head *bh_result, int create)
 786{
 787        /* Block number less than F2FS MAX BLOCKS */
 788        if (unlikely(iblock >= F2FS_I_SB(inode)->max_file_blocks))
 789                return -EFBIG;
 790
 791        return __get_data_block(inode, iblock, bh_result, create,
 792                                                F2FS_GET_BLOCK_BMAP, NULL);
 793}
 794
 795static inline sector_t logical_to_blk(struct inode *inode, loff_t offset)
 796{
 797        return (offset >> inode->i_blkbits);
 798}
 799
 800static inline loff_t blk_to_logical(struct inode *inode, sector_t blk)
 801{
 802        return (blk << inode->i_blkbits);
 803}
 804
 805int f2fs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
 806                u64 start, u64 len)
 807{
 808        struct buffer_head map_bh;
 809        sector_t start_blk, last_blk;
 810        pgoff_t next_pgofs;
 811        loff_t isize;
 812        u64 logical = 0, phys = 0, size = 0;
 813        u32 flags = 0;
 814        int ret = 0;
 815
 816        ret = fiemap_check_flags(fieinfo, FIEMAP_FLAG_SYNC);
 817        if (ret)
 818                return ret;
 819
 820        if (f2fs_has_inline_data(inode)) {
 821                ret = f2fs_inline_data_fiemap(inode, fieinfo, start, len);
 822                if (ret != -EAGAIN)
 823                        return ret;
 824        }
 825
 826        inode_lock(inode);
 827
 828        isize = i_size_read(inode);
 829        if (start >= isize)
 830                goto out;
 831
 832        if (start + len > isize)
 833                len = isize - start;
 834
 835        if (logical_to_blk(inode, len) == 0)
 836                len = blk_to_logical(inode, 1);
 837
 838        start_blk = logical_to_blk(inode, start);
 839        last_blk = logical_to_blk(inode, start + len - 1);
 840
 841next:
 842        memset(&map_bh, 0, sizeof(struct buffer_head));
 843        map_bh.b_size = len;
 844
 845        ret = get_data_block(inode, start_blk, &map_bh, 0,
 846                                        F2FS_GET_BLOCK_FIEMAP, &next_pgofs);
 847        if (ret)
 848                goto out;
 849
 850        /* HOLE */
 851        if (!buffer_mapped(&map_bh)) {
 852                start_blk = next_pgofs;
 853                /* Go through holes util pass the EOF */
 854                if (blk_to_logical(inode, start_blk) < isize)
 855                        goto prep_next;
 856                /* Found a hole beyond isize means no more extents.
 857                 * Note that the premise is that filesystems don't
 858                 * punch holes beyond isize and keep size unchanged.
 859                 */
 860                flags |= FIEMAP_EXTENT_LAST;
 861        }
 862
 863        if (size) {
 864                if (f2fs_encrypted_inode(inode))
 865                        flags |= FIEMAP_EXTENT_DATA_ENCRYPTED;
 866
 867                ret = fiemap_fill_next_extent(fieinfo, logical,
 868                                phys, size, flags);
 869        }
 870
 871        if (start_blk > last_blk || ret)
 872                goto out;
 873
 874        logical = blk_to_logical(inode, start_blk);
 875        phys = blk_to_logical(inode, map_bh.b_blocknr);
 876        size = map_bh.b_size;
 877        flags = 0;
 878        if (buffer_unwritten(&map_bh))
 879                flags = FIEMAP_EXTENT_UNWRITTEN;
 880
 881        start_blk += logical_to_blk(inode, size);
 882
 883prep_next:
 884        cond_resched();
 885        if (fatal_signal_pending(current))
 886                ret = -EINTR;
 887        else
 888                goto next;
 889out:
 890        if (ret == 1)
 891                ret = 0;
 892
 893        inode_unlock(inode);
 894        return ret;
 895}
 896
 897/*
 898 * This function was originally taken from fs/mpage.c, and customized for f2fs.
 899 * Major change was from block_size == page_size in f2fs by default.
 900 */
 901static int f2fs_mpage_readpages(struct address_space *mapping,
 902                        struct list_head *pages, struct page *page,
 903                        unsigned nr_pages)
 904{
 905        struct bio *bio = NULL;
 906        unsigned page_idx;
 907        sector_t last_block_in_bio = 0;
 908        struct inode *inode = mapping->host;
 909        const unsigned blkbits = inode->i_blkbits;
 910        const unsigned blocksize = 1 << blkbits;
 911        sector_t block_in_file;
 912        sector_t last_block;
 913        sector_t last_block_in_file;
 914        sector_t block_nr;
 915        struct block_device *bdev = inode->i_sb->s_bdev;
 916        struct f2fs_map_blocks map;
 917
 918        map.m_pblk = 0;
 919        map.m_lblk = 0;
 920        map.m_len = 0;
 921        map.m_flags = 0;
 922        map.m_next_pgofs = NULL;
 923
 924        for (page_idx = 0; nr_pages; page_idx++, nr_pages--) {
 925
 926                prefetchw(&page->flags);
 927                if (pages) {
 928                        page = list_entry(pages->prev, struct page, lru);
 929                        list_del(&page->lru);
 930                        if (add_to_page_cache_lru(page, mapping,
 931                                                  page->index, GFP_KERNEL))
 932                                goto next_page;
 933                }
 934
 935                block_in_file = (sector_t)page->index;
 936                last_block = block_in_file + nr_pages;
 937                last_block_in_file = (i_size_read(inode) + blocksize - 1) >>
 938                                                                blkbits;
 939                if (last_block > last_block_in_file)
 940                        last_block = last_block_in_file;
 941
 942                /*
 943                 * Map blocks using the previous result first.
 944                 */
 945                if ((map.m_flags & F2FS_MAP_MAPPED) &&
 946                                block_in_file > map.m_lblk &&
 947                                block_in_file < (map.m_lblk + map.m_len))
 948                        goto got_it;
 949
 950                /*
 951                 * Then do more f2fs_map_blocks() calls until we are
 952                 * done with this page.
 953                 */
 954                map.m_flags = 0;
 955
 956                if (block_in_file < last_block) {
 957                        map.m_lblk = block_in_file;
 958                        map.m_len = last_block - block_in_file;
 959
 960                        if (f2fs_map_blocks(inode, &map, 0,
 961                                                F2FS_GET_BLOCK_READ))
 962                                goto set_error_page;
 963                }
 964got_it:
 965                if ((map.m_flags & F2FS_MAP_MAPPED)) {
 966                        block_nr = map.m_pblk + block_in_file - map.m_lblk;
 967                        SetPageMappedToDisk(page);
 968
 969                        if (!PageUptodate(page) && !cleancache_get_page(page)) {
 970                                SetPageUptodate(page);
 971                                goto confused;
 972                        }
 973                } else {
 974                        zero_user_segment(page, 0, PAGE_SIZE);
 975                        SetPageUptodate(page);
 976                        unlock_page(page);
 977                        goto next_page;
 978                }
 979
 980                /*
 981                 * This page will go to BIO.  Do we need to send this
 982                 * BIO off first?
 983                 */
 984                if (bio && (last_block_in_bio != block_nr - 1)) {
 985submit_and_realloc:
 986                        submit_bio(READ, bio);
 987                        bio = NULL;
 988                }
 989                if (bio == NULL) {
 990                        struct fscrypt_ctx *ctx = NULL;
 991
 992                        if (f2fs_encrypted_inode(inode) &&
 993                                        S_ISREG(inode->i_mode)) {
 994
 995                                ctx = fscrypt_get_ctx(inode, GFP_NOFS);
 996                                if (IS_ERR(ctx))
 997                                        goto set_error_page;
 998
 999                                /* wait the page to be moved by cleaning */
1000                                f2fs_wait_on_encrypted_page_writeback(
1001                                                F2FS_I_SB(inode), block_nr);
1002                        }
1003
1004                        bio = bio_alloc(GFP_KERNEL,
1005                                min_t(int, nr_pages, BIO_MAX_PAGES));
1006                        if (!bio) {
1007                                if (ctx)
1008                                        fscrypt_release_ctx(ctx);
1009                                goto set_error_page;
1010                        }
1011                        bio->bi_bdev = bdev;
1012                        bio->bi_iter.bi_sector = SECTOR_FROM_BLOCK(block_nr);
1013                        bio->bi_end_io = f2fs_read_end_io;
1014                        bio->bi_private = ctx;
1015                }
1016
1017                if (bio_add_page(bio, page, blocksize, 0) < blocksize)
1018                        goto submit_and_realloc;
1019
1020                last_block_in_bio = block_nr;
1021                goto next_page;
1022set_error_page:
1023                SetPageError(page);
1024                zero_user_segment(page, 0, PAGE_SIZE);
1025                unlock_page(page);
1026                goto next_page;
1027confused:
1028                if (bio) {
1029                        submit_bio(READ, bio);
1030                        bio = NULL;
1031                }
1032                unlock_page(page);
1033next_page:
1034                if (pages)
1035                        put_page(page);
1036        }
1037        BUG_ON(pages && !list_empty(pages));
1038        if (bio)
1039                submit_bio(READ, bio);
1040        return 0;
1041}
1042
1043static int f2fs_read_data_page(struct file *file, struct page *page)
1044{
1045        struct inode *inode = page->mapping->host;
1046        int ret = -EAGAIN;
1047
1048        trace_f2fs_readpage(page, DATA);
1049
1050        /* If the file has inline data, try to read it directly */
1051        if (f2fs_has_inline_data(inode))
1052                ret = f2fs_read_inline_data(inode, page);
1053        if (ret == -EAGAIN)
1054                ret = f2fs_mpage_readpages(page->mapping, NULL, page, 1);
1055        return ret;
1056}
1057
1058static int f2fs_read_data_pages(struct file *file,
1059                        struct address_space *mapping,
1060                        struct list_head *pages, unsigned nr_pages)
1061{
1062        struct inode *inode = file->f_mapping->host;
1063        struct page *page = list_entry(pages->prev, struct page, lru);
1064
1065        trace_f2fs_readpages(inode, page, nr_pages);
1066
1067        /* If the file has inline data, skip readpages */
1068        if (f2fs_has_inline_data(inode))
1069                return 0;
1070
1071        return f2fs_mpage_readpages(mapping, pages, NULL, nr_pages);
1072}
1073
1074int do_write_data_page(struct f2fs_io_info *fio)
1075{
1076        struct page *page = fio->page;
1077        struct inode *inode = page->mapping->host;
1078        struct dnode_of_data dn;
1079        int err = 0;
1080
1081        set_new_dnode(&dn, inode, NULL, NULL, 0);
1082        err = get_dnode_of_data(&dn, page->index, LOOKUP_NODE);
1083        if (err)
1084                return err;
1085
1086        fio->old_blkaddr = dn.data_blkaddr;
1087
1088        /* This page is already truncated */
1089        if (fio->old_blkaddr == NULL_ADDR) {
1090                ClearPageUptodate(page);
1091                goto out_writepage;
1092        }
1093
1094        if (f2fs_encrypted_inode(inode) && S_ISREG(inode->i_mode)) {
1095                gfp_t gfp_flags = GFP_NOFS;
1096
1097                /* wait for GCed encrypted page writeback */
1098                f2fs_wait_on_encrypted_page_writeback(F2FS_I_SB(inode),
1099                                                        fio->old_blkaddr);
1100retry_encrypt:
1101                fio->encrypted_page = fscrypt_encrypt_page(inode, fio->page,
1102                                                                gfp_flags);
1103                if (IS_ERR(fio->encrypted_page)) {
1104                        err = PTR_ERR(fio->encrypted_page);
1105                        if (err == -ENOMEM) {
1106                                /* flush pending ios and wait for a while */
1107                                f2fs_flush_merged_bios(F2FS_I_SB(inode));
1108                                congestion_wait(BLK_RW_ASYNC, HZ/50);
1109                                gfp_flags |= __GFP_NOFAIL;
1110                                err = 0;
1111                                goto retry_encrypt;
1112                        }
1113                        goto out_writepage;
1114                }
1115        }
1116
1117        set_page_writeback(page);
1118
1119        /*
1120         * If current allocation needs SSR,
1121         * it had better in-place writes for updated data.
1122         */
1123        if (unlikely(fio->old_blkaddr != NEW_ADDR &&
1124                        !is_cold_data(page) &&
1125                        !IS_ATOMIC_WRITTEN_PAGE(page) &&
1126                        need_inplace_update(inode))) {
1127                rewrite_data_page(fio);
1128                set_inode_flag(F2FS_I(inode), FI_UPDATE_WRITE);
1129                trace_f2fs_do_write_data_page(page, IPU);
1130        } else {
1131                write_data_page(&dn, fio);
1132                trace_f2fs_do_write_data_page(page, OPU);
1133                set_inode_flag(F2FS_I(inode), FI_APPEND_WRITE);
1134                if (page->index == 0)
1135                        set_inode_flag(F2FS_I(inode), FI_FIRST_BLOCK_WRITTEN);
1136        }
1137out_writepage:
1138        f2fs_put_dnode(&dn);
1139        return err;
1140}
1141
1142static int f2fs_write_data_page(struct page *page,
1143                                        struct writeback_control *wbc)
1144{
1145        struct inode *inode = page->mapping->host;
1146        struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
1147        loff_t i_size = i_size_read(inode);
1148        const pgoff_t end_index = ((unsigned long long) i_size)
1149                                                        >> PAGE_SHIFT;
1150        unsigned offset = 0;
1151        bool need_balance_fs = false;
1152        int err = 0;
1153        struct f2fs_io_info fio = {
1154                .sbi = sbi,
1155                .type = DATA,
1156                .rw = (wbc->sync_mode == WB_SYNC_ALL) ? WRITE_SYNC : WRITE,
1157                .page = page,
1158                .encrypted_page = NULL,
1159        };
1160
1161        trace_f2fs_writepage(page, DATA);
1162
1163        if (page->index < end_index)
1164                goto write;
1165
1166        /*
1167         * If the offset is out-of-range of file size,
1168         * this page does not have to be written to disk.
1169         */
1170        offset = i_size & (PAGE_SIZE - 1);
1171        if ((page->index >= end_index + 1) || !offset)
1172                goto out;
1173
1174        zero_user_segment(page, offset, PAGE_SIZE);
1175write:
1176        if (unlikely(is_sbi_flag_set(sbi, SBI_POR_DOING)))
1177                goto redirty_out;
1178        if (f2fs_is_drop_cache(inode))
1179                goto out;
1180        if (f2fs_is_volatile_file(inode) && !wbc->for_reclaim &&
1181                        available_free_memory(sbi, BASE_CHECK))
1182                goto redirty_out;
1183
1184        /* Dentry blocks are controlled by checkpoint */
1185        if (S_ISDIR(inode->i_mode)) {
1186                if (unlikely(f2fs_cp_error(sbi)))
1187                        goto redirty_out;
1188                err = do_write_data_page(&fio);
1189                goto done;
1190        }
1191
1192        /* we should bypass data pages to proceed the kworkder jobs */
1193        if (unlikely(f2fs_cp_error(sbi))) {
1194                SetPageError(page);
1195                goto out;
1196        }
1197
1198        if (!wbc->for_reclaim)
1199                need_balance_fs = true;
1200        else if (has_not_enough_free_secs(sbi, 0))
1201                goto redirty_out;
1202
1203        err = -EAGAIN;
1204        f2fs_lock_op(sbi);
1205        if (f2fs_has_inline_data(inode))
1206                err = f2fs_write_inline_data(inode, page);
1207        if (err == -EAGAIN)
1208                err = do_write_data_page(&fio);
1209        f2fs_unlock_op(sbi);
1210done:
1211        if (err && err != -ENOENT)
1212                goto redirty_out;
1213
1214        clear_cold_data(page);
1215out:
1216        inode_dec_dirty_pages(inode);
1217        if (err)
1218                ClearPageUptodate(page);
1219
1220        if (wbc->for_reclaim) {
1221                f2fs_submit_merged_bio_cond(sbi, NULL, page, 0, DATA, WRITE);
1222                remove_dirty_inode(inode);
1223        }
1224
1225        unlock_page(page);
1226        f2fs_balance_fs(sbi, need_balance_fs);
1227
1228        if (unlikely(f2fs_cp_error(sbi)))
1229                f2fs_submit_merged_bio(sbi, DATA, WRITE);
1230
1231        return 0;
1232
1233redirty_out:
1234        redirty_page_for_writepage(wbc, page);
1235        return AOP_WRITEPAGE_ACTIVATE;
1236}
1237
1238static int __f2fs_writepage(struct page *page, struct writeback_control *wbc,
1239                        void *data)
1240{
1241        struct address_space *mapping = data;
1242        int ret = mapping->a_ops->writepage(page, wbc);
1243        mapping_set_error(mapping, ret);
1244        return ret;
1245}
1246
1247/*
1248 * This function was copied from write_cche_pages from mm/page-writeback.c.
1249 * The major change is making write step of cold data page separately from
1250 * warm/hot data page.
1251 */
1252static int f2fs_write_cache_pages(struct address_space *mapping,
1253                        struct writeback_control *wbc, writepage_t writepage,
1254                        void *data)
1255{
1256        int ret = 0;
1257        int done = 0;
1258        struct pagevec pvec;
1259        int nr_pages;
1260        pgoff_t uninitialized_var(writeback_index);
1261        pgoff_t index;
1262        pgoff_t end;            /* Inclusive */
1263        pgoff_t done_index;
1264        int cycled;
1265        int range_whole = 0;
1266        int tag;
1267        int step = 0;
1268
1269        pagevec_init(&pvec, 0);
1270next:
1271        if (wbc->range_cyclic) {
1272                writeback_index = mapping->writeback_index; /* prev offset */
1273                index = writeback_index;
1274                if (index == 0)
1275                        cycled = 1;
1276                else
1277                        cycled = 0;
1278                end = -1;
1279        } else {
1280                index = wbc->range_start >> PAGE_SHIFT;
1281                end = wbc->range_end >> PAGE_SHIFT;
1282                if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
1283                        range_whole = 1;
1284                cycled = 1; /* ignore range_cyclic tests */
1285        }
1286        if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)
1287                tag = PAGECACHE_TAG_TOWRITE;
1288        else
1289                tag = PAGECACHE_TAG_DIRTY;
1290retry:
1291        if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)
1292                tag_pages_for_writeback(mapping, index, end);
1293        done_index = index;
1294        while (!done && (index <= end)) {
1295                int i;
1296
1297                nr_pages = pagevec_lookup_tag(&pvec, mapping, &index, tag,
1298                              min(end - index, (pgoff_t)PAGEVEC_SIZE - 1) + 1);
1299                if (nr_pages == 0)
1300                        break;
1301
1302                for (i = 0; i < nr_pages; i++) {
1303                        struct page *page = pvec.pages[i];
1304
1305                        if (page->index > end) {
1306                                done = 1;
1307                                break;
1308                        }
1309
1310                        done_index = page->index;
1311
1312                        lock_page(page);
1313
1314                        if (unlikely(page->mapping != mapping)) {
1315continue_unlock:
1316                                unlock_page(page);
1317                                continue;
1318                        }
1319
1320                        if (!PageDirty(page)) {
1321                                /* someone wrote it for us */
1322                                goto continue_unlock;
1323                        }
1324
1325                        if (step == is_cold_data(page))
1326                                goto continue_unlock;
1327
1328                        if (PageWriteback(page)) {
1329                                if (wbc->sync_mode != WB_SYNC_NONE)
1330                                        f2fs_wait_on_page_writeback(page,
1331                                                                DATA, true);
1332                                else
1333                                        goto continue_unlock;
1334                        }
1335
1336                        BUG_ON(PageWriteback(page));
1337                        if (!clear_page_dirty_for_io(page))
1338                                goto continue_unlock;
1339
1340                        ret = (*writepage)(page, wbc, data);
1341                        if (unlikely(ret)) {
1342                                if (ret == AOP_WRITEPAGE_ACTIVATE) {
1343                                        unlock_page(page);
1344                                        ret = 0;
1345                                } else {
1346                                        done_index = page->index + 1;
1347                                        done = 1;
1348                                        break;
1349                                }
1350                        }
1351
1352                        if (--wbc->nr_to_write <= 0 &&
1353                            wbc->sync_mode == WB_SYNC_NONE) {
1354                                done = 1;
1355                                break;
1356                        }
1357                }
1358                pagevec_release(&pvec);
1359                cond_resched();
1360        }
1361
1362        if (step < 1) {
1363                step++;
1364                goto next;
1365        }
1366
1367        if (!cycled && !done) {
1368                cycled = 1;
1369                index = 0;
1370                end = writeback_index - 1;
1371                goto retry;
1372        }
1373        if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
1374                mapping->writeback_index = done_index;
1375
1376        return ret;
1377}
1378
1379static int f2fs_write_data_pages(struct address_space *mapping,
1380                            struct writeback_control *wbc)
1381{
1382        struct inode *inode = mapping->host;
1383        struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
1384        bool locked = false;
1385        int ret;
1386        long diff;
1387
1388        /* deal with chardevs and other special file */
1389        if (!mapping->a_ops->writepage)
1390                return 0;
1391
1392        /* skip writing if there is no dirty page in this inode */
1393        if (!get_dirty_pages(inode) && wbc->sync_mode == WB_SYNC_NONE)
1394                return 0;
1395
1396        if (S_ISDIR(inode->i_mode) && wbc->sync_mode == WB_SYNC_NONE &&
1397                        get_dirty_pages(inode) < nr_pages_to_skip(sbi, DATA) &&
1398                        available_free_memory(sbi, DIRTY_DENTS))
1399                goto skip_write;
1400
1401        /* skip writing during file defragment */
1402        if (is_inode_flag_set(F2FS_I(inode), FI_DO_DEFRAG))
1403                goto skip_write;
1404
1405        /* during POR, we don't need to trigger writepage at all. */
1406        if (unlikely(is_sbi_flag_set(sbi, SBI_POR_DOING)))
1407                goto skip_write;
1408
1409        trace_f2fs_writepages(mapping->host, wbc, DATA);
1410
1411        diff = nr_pages_to_write(sbi, DATA, wbc);
1412
1413        if (!S_ISDIR(inode->i_mode) && wbc->sync_mode == WB_SYNC_ALL) {
1414                mutex_lock(&sbi->writepages);
1415                locked = true;
1416        }
1417        ret = f2fs_write_cache_pages(mapping, wbc, __f2fs_writepage, mapping);
1418        f2fs_submit_merged_bio_cond(sbi, inode, NULL, 0, DATA, WRITE);
1419        if (locked)
1420                mutex_unlock(&sbi->writepages);
1421
1422        remove_dirty_inode(inode);
1423
1424        wbc->nr_to_write = max((long)0, wbc->nr_to_write - diff);
1425        return ret;
1426
1427skip_write:
1428        wbc->pages_skipped += get_dirty_pages(inode);
1429        trace_f2fs_writepages(mapping->host, wbc, DATA);
1430        return 0;
1431}
1432
1433static void f2fs_write_failed(struct address_space *mapping, loff_t to)
1434{
1435        struct inode *inode = mapping->host;
1436        loff_t i_size = i_size_read(inode);
1437
1438        if (to > i_size) {
1439                truncate_pagecache(inode, i_size);
1440                truncate_blocks(inode, i_size, true);
1441        }
1442}
1443
1444static int prepare_write_begin(struct f2fs_sb_info *sbi,
1445                        struct page *page, loff_t pos, unsigned len,
1446                        block_t *blk_addr, bool *node_changed)
1447{
1448        struct inode *inode = page->mapping->host;
1449        pgoff_t index = page->index;
1450        struct dnode_of_data dn;
1451        struct page *ipage;
1452        bool locked = false;
1453        struct extent_info ei;
1454        int err = 0;
1455
1456        /*
1457         * we already allocated all the blocks, so we don't need to get
1458         * the block addresses when there is no need to fill the page.
1459         */
1460        if (!f2fs_has_inline_data(inode) && !f2fs_encrypted_inode(inode) &&
1461                                        len == PAGE_SIZE)
1462                return 0;
1463
1464        if (f2fs_has_inline_data(inode) ||
1465                        (pos & PAGE_MASK) >= i_size_read(inode)) {
1466                f2fs_lock_op(sbi);
1467                locked = true;
1468        }
1469restart:
1470        /* check inline_data */
1471        ipage = get_node_page(sbi, inode->i_ino);
1472        if (IS_ERR(ipage)) {
1473                err = PTR_ERR(ipage);
1474                goto unlock_out;
1475        }
1476
1477        set_new_dnode(&dn, inode, ipage, ipage, 0);
1478
1479        if (f2fs_has_inline_data(inode)) {
1480                if (pos + len <= MAX_INLINE_DATA) {
1481                        read_inline_data(page, ipage);
1482                        set_inode_flag(F2FS_I(inode), FI_DATA_EXIST);
1483                        set_inline_node(ipage);
1484                } else {
1485                        err = f2fs_convert_inline_page(&dn, page);
1486                        if (err)
1487                                goto out;
1488                        if (dn.data_blkaddr == NULL_ADDR)
1489                                err = f2fs_get_block(&dn, index);
1490                }
1491        } else if (locked) {
1492                err = f2fs_get_block(&dn, index);
1493        } else {
1494                if (f2fs_lookup_extent_cache(inode, index, &ei)) {
1495                        dn.data_blkaddr = ei.blk + index - ei.fofs;
1496                } else {
1497                        /* hole case */
1498                        err = get_dnode_of_data(&dn, index, LOOKUP_NODE);
1499                        if (err || (!err && dn.data_blkaddr == NULL_ADDR)) {
1500                                f2fs_put_dnode(&dn);
1501                                f2fs_lock_op(sbi);
1502                                locked = true;
1503                                goto restart;
1504                        }
1505                }
1506        }
1507
1508        /* convert_inline_page can make node_changed */
1509        *blk_addr = dn.data_blkaddr;
1510        *node_changed = dn.node_changed;
1511out:
1512        f2fs_put_dnode(&dn);
1513unlock_out:
1514        if (locked)
1515                f2fs_unlock_op(sbi);
1516        return err;
1517}
1518
1519static int f2fs_write_begin(struct file *file, struct address_space *mapping,
1520                loff_t pos, unsigned len, unsigned flags,
1521                struct page **pagep, void **fsdata)
1522{
1523        struct inode *inode = mapping->host;
1524        struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
1525        struct page *page = NULL;
1526        pgoff_t index = ((unsigned long long) pos) >> PAGE_SHIFT;
1527        bool need_balance = false;
1528        block_t blkaddr = NULL_ADDR;
1529        int err = 0;
1530
1531        trace_f2fs_write_begin(inode, pos, len, flags);
1532
1533        /*
1534         * We should check this at this moment to avoid deadlock on inode page
1535         * and #0 page. The locking rule for inline_data conversion should be:
1536         * lock_page(page #0) -> lock_page(inode_page)
1537         */
1538        if (index != 0) {
1539                err = f2fs_convert_inline_inode(inode);
1540                if (err)
1541                        goto fail;
1542        }
1543repeat:
1544        page = grab_cache_page_write_begin(mapping, index, flags);
1545        if (!page) {
1546                err = -ENOMEM;
1547                goto fail;
1548        }
1549
1550        *pagep = page;
1551
1552        err = prepare_write_begin(sbi, page, pos, len,
1553                                        &blkaddr, &need_balance);
1554        if (err)
1555                goto fail;
1556
1557        if (need_balance && has_not_enough_free_secs(sbi, 0)) {
1558                unlock_page(page);
1559                f2fs_balance_fs(sbi, true);
1560                lock_page(page);
1561                if (page->mapping != mapping) {
1562                        /* The page got truncated from under us */
1563                        f2fs_put_page(page, 1);
1564                        goto repeat;
1565                }
1566        }
1567
1568        f2fs_wait_on_page_writeback(page, DATA, false);
1569
1570        /* wait for GCed encrypted page writeback */
1571        if (f2fs_encrypted_inode(inode) && S_ISREG(inode->i_mode))
1572                f2fs_wait_on_encrypted_page_writeback(sbi, blkaddr);
1573
1574        if (len == PAGE_SIZE)
1575                goto out_update;
1576        if (PageUptodate(page))
1577                goto out_clear;
1578
1579        if ((pos & PAGE_MASK) >= i_size_read(inode)) {
1580                unsigned start = pos & (PAGE_SIZE - 1);
1581                unsigned end = start + len;
1582
1583                /* Reading beyond i_size is simple: memset to zero */
1584                zero_user_segments(page, 0, start, end, PAGE_SIZE);
1585                goto out_update;
1586        }
1587
1588        if (blkaddr == NEW_ADDR) {
1589                zero_user_segment(page, 0, PAGE_SIZE);
1590        } else {
1591                struct f2fs_io_info fio = {
1592                        .sbi = sbi,
1593                        .type = DATA,
1594                        .rw = READ_SYNC,
1595                        .old_blkaddr = blkaddr,
1596                        .new_blkaddr = blkaddr,
1597                        .page = page,
1598                        .encrypted_page = NULL,
1599                };
1600                err = f2fs_submit_page_bio(&fio);
1601                if (err)
1602                        goto fail;
1603
1604                lock_page(page);
1605                if (unlikely(!PageUptodate(page))) {
1606                        err = -EIO;
1607                        goto fail;
1608                }
1609                if (unlikely(page->mapping != mapping)) {
1610                        f2fs_put_page(page, 1);
1611                        goto repeat;
1612                }
1613
1614                /* avoid symlink page */
1615                if (f2fs_encrypted_inode(inode) && S_ISREG(inode->i_mode)) {
1616                        err = fscrypt_decrypt_page(page);
1617                        if (err)
1618                                goto fail;
1619                }
1620        }
1621out_update:
1622        SetPageUptodate(page);
1623out_clear:
1624        clear_cold_data(page);
1625        return 0;
1626
1627fail:
1628        f2fs_put_page(page, 1);
1629        f2fs_write_failed(mapping, pos + len);
1630        return err;
1631}
1632
1633static int f2fs_write_end(struct file *file,
1634                        struct address_space *mapping,
1635                        loff_t pos, unsigned len, unsigned copied,
1636                        struct page *page, void *fsdata)
1637{
1638        struct inode *inode = page->mapping->host;
1639
1640        trace_f2fs_write_end(inode, pos, len, copied);
1641
1642        set_page_dirty(page);
1643
1644        if (pos + copied > i_size_read(inode)) {
1645                i_size_write(inode, pos + copied);
1646                mark_inode_dirty(inode);
1647        }
1648
1649        f2fs_put_page(page, 1);
1650        f2fs_update_time(F2FS_I_SB(inode), REQ_TIME);
1651        return copied;
1652}
1653
1654static int check_direct_IO(struct inode *inode, struct iov_iter *iter,
1655                           loff_t offset)
1656{
1657        unsigned blocksize_mask = inode->i_sb->s_blocksize - 1;
1658
1659        if (offset & blocksize_mask)
1660                return -EINVAL;
1661
1662        if (iov_iter_alignment(iter) & blocksize_mask)
1663                return -EINVAL;
1664
1665        return 0;
1666}
1667
1668static ssize_t f2fs_direct_IO(struct kiocb *iocb, struct iov_iter *iter,
1669                              loff_t offset)
1670{
1671        struct address_space *mapping = iocb->ki_filp->f_mapping;
1672        struct inode *inode = mapping->host;
1673        size_t count = iov_iter_count(iter);
1674        int err;
1675
1676        err = check_direct_IO(inode, iter, offset);
1677        if (err)
1678                return err;
1679
1680        if (f2fs_encrypted_inode(inode) && S_ISREG(inode->i_mode))
1681                return 0;
1682
1683        trace_f2fs_direct_IO_enter(inode, offset, count, iov_iter_rw(iter));
1684
1685        err = blockdev_direct_IO(iocb, inode, iter, offset, get_data_block_dio);
1686        if (err < 0 && iov_iter_rw(iter) == WRITE)
1687                f2fs_write_failed(mapping, offset + count);
1688
1689        trace_f2fs_direct_IO_exit(inode, offset, count, iov_iter_rw(iter), err);
1690
1691        return err;
1692}
1693
1694void f2fs_invalidate_page(struct page *page, unsigned int offset,
1695                                                        unsigned int length)
1696{
1697        struct inode *inode = page->mapping->host;
1698        struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
1699
1700        if (inode->i_ino >= F2FS_ROOT_INO(sbi) &&
1701                (offset % PAGE_SIZE || length != PAGE_SIZE))
1702                return;
1703
1704        if (PageDirty(page)) {
1705                if (inode->i_ino == F2FS_META_INO(sbi))
1706                        dec_page_count(sbi, F2FS_DIRTY_META);
1707                else if (inode->i_ino == F2FS_NODE_INO(sbi))
1708                        dec_page_count(sbi, F2FS_DIRTY_NODES);
1709                else
1710                        inode_dec_dirty_pages(inode);
1711        }
1712
1713        /* This is atomic written page, keep Private */
1714        if (IS_ATOMIC_WRITTEN_PAGE(page))
1715                return;
1716
1717        ClearPagePrivate(page);
1718}
1719
1720int f2fs_release_page(struct page *page, gfp_t wait)
1721{
1722        /* If this is dirty page, keep PagePrivate */
1723        if (PageDirty(page))
1724                return 0;
1725
1726        /* This is atomic written page, keep Private */
1727        if (IS_ATOMIC_WRITTEN_PAGE(page))
1728                return 0;
1729
1730        ClearPagePrivate(page);
1731        return 1;
1732}
1733
1734static int f2fs_set_data_page_dirty(struct page *page)
1735{
1736        struct address_space *mapping = page->mapping;
1737        struct inode *inode = mapping->host;
1738
1739        trace_f2fs_set_page_dirty(page, DATA);
1740
1741        SetPageUptodate(page);
1742
1743        if (f2fs_is_atomic_file(inode)) {
1744                if (!IS_ATOMIC_WRITTEN_PAGE(page)) {
1745                        register_inmem_page(inode, page);
1746                        return 1;
1747                }
1748                /*
1749                 * Previously, this page has been registered, we just
1750                 * return here.
1751                 */
1752                return 0;
1753        }
1754
1755        if (!PageDirty(page)) {
1756                __set_page_dirty_nobuffers(page);
1757                update_dirty_page(inode, page);
1758                return 1;
1759        }
1760        return 0;
1761}
1762
1763static sector_t f2fs_bmap(struct address_space *mapping, sector_t block)
1764{
1765        struct inode *inode = mapping->host;
1766
1767        if (f2fs_has_inline_data(inode))
1768                return 0;
1769
1770        /* make sure allocating whole blocks */
1771        if (mapping_tagged(mapping, PAGECACHE_TAG_DIRTY))
1772                filemap_write_and_wait(mapping);
1773
1774        return generic_block_bmap(mapping, block, get_data_block_bmap);
1775}
1776
1777const struct address_space_operations f2fs_dblock_aops = {
1778        .readpage       = f2fs_read_data_page,
1779        .readpages      = f2fs_read_data_pages,
1780        .writepage      = f2fs_write_data_page,
1781        .writepages     = f2fs_write_data_pages,
1782        .write_begin    = f2fs_write_begin,
1783        .write_end      = f2fs_write_end,
1784        .set_page_dirty = f2fs_set_data_page_dirty,
1785        .invalidatepage = f2fs_invalidate_page,
1786        .releasepage    = f2fs_release_page,
1787        .direct_IO      = f2fs_direct_IO,
1788        .bmap           = f2fs_bmap,
1789};
1790