linux/fs/f2fs/dir.c
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   1/*
   2 * fs/f2fs/dir.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 "f2fs.h"
  14#include "node.h"
  15#include "acl.h"
  16#include "xattr.h"
  17
  18static unsigned long dir_blocks(struct inode *inode)
  19{
  20        return ((unsigned long long) (i_size_read(inode) + PAGE_CACHE_SIZE - 1))
  21                                                        >> PAGE_CACHE_SHIFT;
  22}
  23
  24static unsigned int dir_buckets(unsigned int level, int dir_level)
  25{
  26        if (level + dir_level < MAX_DIR_HASH_DEPTH / 2)
  27                return 1 << (level + dir_level);
  28        else
  29                return MAX_DIR_BUCKETS;
  30}
  31
  32static unsigned int bucket_blocks(unsigned int level)
  33{
  34        if (level < MAX_DIR_HASH_DEPTH / 2)
  35                return 2;
  36        else
  37                return 4;
  38}
  39
  40static unsigned char f2fs_filetype_table[F2FS_FT_MAX] = {
  41        [F2FS_FT_UNKNOWN]       = DT_UNKNOWN,
  42        [F2FS_FT_REG_FILE]      = DT_REG,
  43        [F2FS_FT_DIR]           = DT_DIR,
  44        [F2FS_FT_CHRDEV]        = DT_CHR,
  45        [F2FS_FT_BLKDEV]        = DT_BLK,
  46        [F2FS_FT_FIFO]          = DT_FIFO,
  47        [F2FS_FT_SOCK]          = DT_SOCK,
  48        [F2FS_FT_SYMLINK]       = DT_LNK,
  49};
  50
  51#define S_SHIFT 12
  52static unsigned char f2fs_type_by_mode[S_IFMT >> S_SHIFT] = {
  53        [S_IFREG >> S_SHIFT]    = F2FS_FT_REG_FILE,
  54        [S_IFDIR >> S_SHIFT]    = F2FS_FT_DIR,
  55        [S_IFCHR >> S_SHIFT]    = F2FS_FT_CHRDEV,
  56        [S_IFBLK >> S_SHIFT]    = F2FS_FT_BLKDEV,
  57        [S_IFIFO >> S_SHIFT]    = F2FS_FT_FIFO,
  58        [S_IFSOCK >> S_SHIFT]   = F2FS_FT_SOCK,
  59        [S_IFLNK >> S_SHIFT]    = F2FS_FT_SYMLINK,
  60};
  61
  62static void set_de_type(struct f2fs_dir_entry *de, struct inode *inode)
  63{
  64        umode_t mode = inode->i_mode;
  65        de->file_type = f2fs_type_by_mode[(mode & S_IFMT) >> S_SHIFT];
  66}
  67
  68static unsigned long dir_block_index(unsigned int level,
  69                                int dir_level, unsigned int idx)
  70{
  71        unsigned long i;
  72        unsigned long bidx = 0;
  73
  74        for (i = 0; i < level; i++)
  75                bidx += dir_buckets(i, dir_level) * bucket_blocks(i);
  76        bidx += idx * bucket_blocks(level);
  77        return bidx;
  78}
  79
  80static bool early_match_name(size_t namelen, f2fs_hash_t namehash,
  81                                struct f2fs_dir_entry *de)
  82{
  83        if (le16_to_cpu(de->name_len) != namelen)
  84                return false;
  85
  86        if (de->hash_code != namehash)
  87                return false;
  88
  89        return true;
  90}
  91
  92static struct f2fs_dir_entry *find_in_block(struct page *dentry_page,
  93                        struct qstr *name, int *max_slots,
  94                        f2fs_hash_t namehash, struct page **res_page)
  95{
  96        struct f2fs_dir_entry *de;
  97        unsigned long bit_pos = 0;
  98        struct f2fs_dentry_block *dentry_blk = kmap(dentry_page);
  99        const void *dentry_bits = &dentry_blk->dentry_bitmap;
 100        int max_len = 0;
 101
 102        while (bit_pos < NR_DENTRY_IN_BLOCK) {
 103                if (!test_bit_le(bit_pos, dentry_bits)) {
 104                        if (bit_pos == 0)
 105                                max_len = 1;
 106                        else if (!test_bit_le(bit_pos - 1, dentry_bits))
 107                                max_len++;
 108                        bit_pos++;
 109                        continue;
 110                }
 111                de = &dentry_blk->dentry[bit_pos];
 112                if (early_match_name(name->len, namehash, de)) {
 113                        if (!memcmp(dentry_blk->filename[bit_pos],
 114                                                        name->name,
 115                                                        name->len)) {
 116                                *res_page = dentry_page;
 117                                goto found;
 118                        }
 119                }
 120                if (max_len > *max_slots) {
 121                        *max_slots = max_len;
 122                        max_len = 0;
 123                }
 124
 125                /*
 126                 * For the most part, it should be a bug when name_len is zero.
 127                 * We stop here for figuring out where the bugs has occurred.
 128                 */
 129                f2fs_bug_on(F2FS_P_SB(dentry_page), !de->name_len);
 130
 131                bit_pos += GET_DENTRY_SLOTS(le16_to_cpu(de->name_len));
 132        }
 133
 134        de = NULL;
 135        kunmap(dentry_page);
 136found:
 137        if (max_len > *max_slots)
 138                *max_slots = max_len;
 139        return de;
 140}
 141
 142static struct f2fs_dir_entry *find_in_level(struct inode *dir,
 143                        unsigned int level, struct qstr *name,
 144                        f2fs_hash_t namehash, struct page **res_page)
 145{
 146        int s = GET_DENTRY_SLOTS(name->len);
 147        unsigned int nbucket, nblock;
 148        unsigned int bidx, end_block;
 149        struct page *dentry_page;
 150        struct f2fs_dir_entry *de = NULL;
 151        bool room = false;
 152        int max_slots = 0;
 153
 154        f2fs_bug_on(F2FS_I_SB(dir), level > MAX_DIR_HASH_DEPTH);
 155
 156        nbucket = dir_buckets(level, F2FS_I(dir)->i_dir_level);
 157        nblock = bucket_blocks(level);
 158
 159        bidx = dir_block_index(level, F2FS_I(dir)->i_dir_level,
 160                                        le32_to_cpu(namehash) % nbucket);
 161        end_block = bidx + nblock;
 162
 163        for (; bidx < end_block; bidx++) {
 164                /* no need to allocate new dentry pages to all the indices */
 165                dentry_page = find_data_page(dir, bidx, true);
 166                if (IS_ERR(dentry_page)) {
 167                        room = true;
 168                        continue;
 169                }
 170
 171                de = find_in_block(dentry_page, name, &max_slots,
 172                                        namehash, res_page);
 173                if (de)
 174                        break;
 175
 176                if (max_slots >= s)
 177                        room = true;
 178                f2fs_put_page(dentry_page, 0);
 179        }
 180
 181        if (!de && room && F2FS_I(dir)->chash != namehash) {
 182                F2FS_I(dir)->chash = namehash;
 183                F2FS_I(dir)->clevel = level;
 184        }
 185
 186        return de;
 187}
 188
 189/*
 190 * Find an entry in the specified directory with the wanted name.
 191 * It returns the page where the entry was found (as a parameter - res_page),
 192 * and the entry itself. Page is returned mapped and unlocked.
 193 * Entry is guaranteed to be valid.
 194 */
 195struct f2fs_dir_entry *f2fs_find_entry(struct inode *dir,
 196                        struct qstr *child, struct page **res_page)
 197{
 198        unsigned long npages = dir_blocks(dir);
 199        struct f2fs_dir_entry *de = NULL;
 200        f2fs_hash_t name_hash;
 201        unsigned int max_depth;
 202        unsigned int level;
 203
 204        if (npages == 0)
 205                return NULL;
 206
 207        *res_page = NULL;
 208
 209        name_hash = f2fs_dentry_hash(child);
 210        max_depth = F2FS_I(dir)->i_current_depth;
 211
 212        for (level = 0; level < max_depth; level++) {
 213                de = find_in_level(dir, level, child, name_hash, res_page);
 214                if (de)
 215                        break;
 216        }
 217        if (!de && F2FS_I(dir)->chash != name_hash) {
 218                F2FS_I(dir)->chash = name_hash;
 219                F2FS_I(dir)->clevel = level - 1;
 220        }
 221        return de;
 222}
 223
 224struct f2fs_dir_entry *f2fs_parent_dir(struct inode *dir, struct page **p)
 225{
 226        struct page *page;
 227        struct f2fs_dir_entry *de;
 228        struct f2fs_dentry_block *dentry_blk;
 229
 230        page = get_lock_data_page(dir, 0);
 231        if (IS_ERR(page))
 232                return NULL;
 233
 234        dentry_blk = kmap(page);
 235        de = &dentry_blk->dentry[1];
 236        *p = page;
 237        unlock_page(page);
 238        return de;
 239}
 240
 241ino_t f2fs_inode_by_name(struct inode *dir, struct qstr *qstr)
 242{
 243        ino_t res = 0;
 244        struct f2fs_dir_entry *de;
 245        struct page *page;
 246
 247        de = f2fs_find_entry(dir, qstr, &page);
 248        if (de) {
 249                res = le32_to_cpu(de->ino);
 250                kunmap(page);
 251                f2fs_put_page(page, 0);
 252        }
 253
 254        return res;
 255}
 256
 257void f2fs_set_link(struct inode *dir, struct f2fs_dir_entry *de,
 258                struct page *page, struct inode *inode)
 259{
 260        lock_page(page);
 261        f2fs_wait_on_page_writeback(page, DATA);
 262        de->ino = cpu_to_le32(inode->i_ino);
 263        set_de_type(de, inode);
 264        kunmap(page);
 265        set_page_dirty(page);
 266        dir->i_mtime = dir->i_ctime = CURRENT_TIME;
 267        mark_inode_dirty(dir);
 268
 269        f2fs_put_page(page, 1);
 270}
 271
 272static void init_dent_inode(const struct qstr *name, struct page *ipage)
 273{
 274        struct f2fs_inode *ri;
 275
 276        f2fs_wait_on_page_writeback(ipage, NODE);
 277
 278        /* copy name info. to this inode page */
 279        ri = F2FS_INODE(ipage);
 280        ri->i_namelen = cpu_to_le32(name->len);
 281        memcpy(ri->i_name, name->name, name->len);
 282        set_page_dirty(ipage);
 283}
 284
 285int update_dent_inode(struct inode *inode, const struct qstr *name)
 286{
 287        struct page *page;
 288
 289        page = get_node_page(F2FS_I_SB(inode), inode->i_ino);
 290        if (IS_ERR(page))
 291                return PTR_ERR(page);
 292
 293        init_dent_inode(name, page);
 294        f2fs_put_page(page, 1);
 295
 296        return 0;
 297}
 298
 299static int make_empty_dir(struct inode *inode,
 300                struct inode *parent, struct page *page)
 301{
 302        struct page *dentry_page;
 303        struct f2fs_dentry_block *dentry_blk;
 304        struct f2fs_dir_entry *de;
 305
 306        dentry_page = get_new_data_page(inode, page, 0, true);
 307        if (IS_ERR(dentry_page))
 308                return PTR_ERR(dentry_page);
 309
 310
 311        dentry_blk = kmap_atomic(dentry_page);
 312
 313        de = &dentry_blk->dentry[0];
 314        de->name_len = cpu_to_le16(1);
 315        de->hash_code = 0;
 316        de->ino = cpu_to_le32(inode->i_ino);
 317        memcpy(dentry_blk->filename[0], ".", 1);
 318        set_de_type(de, inode);
 319
 320        de = &dentry_blk->dentry[1];
 321        de->hash_code = 0;
 322        de->name_len = cpu_to_le16(2);
 323        de->ino = cpu_to_le32(parent->i_ino);
 324        memcpy(dentry_blk->filename[1], "..", 2);
 325        set_de_type(de, inode);
 326
 327        test_and_set_bit_le(0, &dentry_blk->dentry_bitmap);
 328        test_and_set_bit_le(1, &dentry_blk->dentry_bitmap);
 329        kunmap_atomic(dentry_blk);
 330
 331        set_page_dirty(dentry_page);
 332        f2fs_put_page(dentry_page, 1);
 333        return 0;
 334}
 335
 336static struct page *init_inode_metadata(struct inode *inode,
 337                struct inode *dir, const struct qstr *name)
 338{
 339        struct page *page;
 340        int err;
 341
 342        if (is_inode_flag_set(F2FS_I(inode), FI_NEW_INODE)) {
 343                page = new_inode_page(inode);
 344                if (IS_ERR(page))
 345                        return page;
 346
 347                if (S_ISDIR(inode->i_mode)) {
 348                        err = make_empty_dir(inode, dir, page);
 349                        if (err)
 350                                goto error;
 351                }
 352
 353                err = f2fs_init_acl(inode, dir, page);
 354                if (err)
 355                        goto put_error;
 356
 357                err = f2fs_init_security(inode, dir, name, page);
 358                if (err)
 359                        goto put_error;
 360        } else {
 361                page = get_node_page(F2FS_I_SB(dir), inode->i_ino);
 362                if (IS_ERR(page))
 363                        return page;
 364
 365                set_cold_node(inode, page);
 366        }
 367
 368        if (name)
 369                init_dent_inode(name, page);
 370
 371        /*
 372         * This file should be checkpointed during fsync.
 373         * We lost i_pino from now on.
 374         */
 375        if (is_inode_flag_set(F2FS_I(inode), FI_INC_LINK)) {
 376                file_lost_pino(inode);
 377                /*
 378                 * If link the tmpfile to alias through linkat path,
 379                 * we should remove this inode from orphan list.
 380                 */
 381                if (inode->i_nlink == 0)
 382                        remove_orphan_inode(F2FS_I_SB(dir), inode->i_ino);
 383                inc_nlink(inode);
 384        }
 385        return page;
 386
 387put_error:
 388        f2fs_put_page(page, 1);
 389error:
 390        /* once the failed inode becomes a bad inode, i_mode is S_IFREG */
 391        truncate_inode_pages(&inode->i_data, 0);
 392        truncate_blocks(inode, 0, false);
 393        remove_dirty_dir_inode(inode);
 394        remove_inode_page(inode);
 395        return ERR_PTR(err);
 396}
 397
 398static void update_parent_metadata(struct inode *dir, struct inode *inode,
 399                                                unsigned int current_depth)
 400{
 401        if (is_inode_flag_set(F2FS_I(inode), FI_NEW_INODE)) {
 402                if (S_ISDIR(inode->i_mode)) {
 403                        inc_nlink(dir);
 404                        set_inode_flag(F2FS_I(dir), FI_UPDATE_DIR);
 405                }
 406                clear_inode_flag(F2FS_I(inode), FI_NEW_INODE);
 407        }
 408        dir->i_mtime = dir->i_ctime = CURRENT_TIME;
 409        mark_inode_dirty(dir);
 410
 411        if (F2FS_I(dir)->i_current_depth != current_depth) {
 412                F2FS_I(dir)->i_current_depth = current_depth;
 413                set_inode_flag(F2FS_I(dir), FI_UPDATE_DIR);
 414        }
 415
 416        if (is_inode_flag_set(F2FS_I(inode), FI_INC_LINK))
 417                clear_inode_flag(F2FS_I(inode), FI_INC_LINK);
 418}
 419
 420static int room_for_filename(struct f2fs_dentry_block *dentry_blk, int slots)
 421{
 422        int bit_start = 0;
 423        int zero_start, zero_end;
 424next:
 425        zero_start = find_next_zero_bit_le(&dentry_blk->dentry_bitmap,
 426                                                NR_DENTRY_IN_BLOCK,
 427                                                bit_start);
 428        if (zero_start >= NR_DENTRY_IN_BLOCK)
 429                return NR_DENTRY_IN_BLOCK;
 430
 431        zero_end = find_next_bit_le(&dentry_blk->dentry_bitmap,
 432                                                NR_DENTRY_IN_BLOCK,
 433                                                zero_start);
 434        if (zero_end - zero_start >= slots)
 435                return zero_start;
 436
 437        bit_start = zero_end + 1;
 438
 439        if (zero_end + 1 >= NR_DENTRY_IN_BLOCK)
 440                return NR_DENTRY_IN_BLOCK;
 441        goto next;
 442}
 443
 444/*
 445 * Caller should grab and release a rwsem by calling f2fs_lock_op() and
 446 * f2fs_unlock_op().
 447 */
 448int __f2fs_add_link(struct inode *dir, const struct qstr *name,
 449                                                struct inode *inode)
 450{
 451        unsigned int bit_pos;
 452        unsigned int level;
 453        unsigned int current_depth;
 454        unsigned long bidx, block;
 455        f2fs_hash_t dentry_hash;
 456        struct f2fs_dir_entry *de;
 457        unsigned int nbucket, nblock;
 458        size_t namelen = name->len;
 459        struct page *dentry_page = NULL;
 460        struct f2fs_dentry_block *dentry_blk = NULL;
 461        int slots = GET_DENTRY_SLOTS(namelen);
 462        struct page *page;
 463        int err = 0;
 464        int i;
 465
 466        dentry_hash = f2fs_dentry_hash(name);
 467        level = 0;
 468        current_depth = F2FS_I(dir)->i_current_depth;
 469        if (F2FS_I(dir)->chash == dentry_hash) {
 470                level = F2FS_I(dir)->clevel;
 471                F2FS_I(dir)->chash = 0;
 472        }
 473
 474start:
 475        if (unlikely(current_depth == MAX_DIR_HASH_DEPTH))
 476                return -ENOSPC;
 477
 478        /* Increase the depth, if required */
 479        if (level == current_depth)
 480                ++current_depth;
 481
 482        nbucket = dir_buckets(level, F2FS_I(dir)->i_dir_level);
 483        nblock = bucket_blocks(level);
 484
 485        bidx = dir_block_index(level, F2FS_I(dir)->i_dir_level,
 486                                (le32_to_cpu(dentry_hash) % nbucket));
 487
 488        for (block = bidx; block <= (bidx + nblock - 1); block++) {
 489                dentry_page = get_new_data_page(dir, NULL, block, true);
 490                if (IS_ERR(dentry_page))
 491                        return PTR_ERR(dentry_page);
 492
 493                dentry_blk = kmap(dentry_page);
 494                bit_pos = room_for_filename(dentry_blk, slots);
 495                if (bit_pos < NR_DENTRY_IN_BLOCK)
 496                        goto add_dentry;
 497
 498                kunmap(dentry_page);
 499                f2fs_put_page(dentry_page, 1);
 500        }
 501
 502        /* Move to next level to find the empty slot for new dentry */
 503        ++level;
 504        goto start;
 505add_dentry:
 506        f2fs_wait_on_page_writeback(dentry_page, DATA);
 507
 508        down_write(&F2FS_I(inode)->i_sem);
 509        page = init_inode_metadata(inode, dir, name);
 510        if (IS_ERR(page)) {
 511                err = PTR_ERR(page);
 512                goto fail;
 513        }
 514        de = &dentry_blk->dentry[bit_pos];
 515        de->hash_code = dentry_hash;
 516        de->name_len = cpu_to_le16(namelen);
 517        memcpy(dentry_blk->filename[bit_pos], name->name, name->len);
 518        de->ino = cpu_to_le32(inode->i_ino);
 519        set_de_type(de, inode);
 520        for (i = 0; i < slots; i++)
 521                test_and_set_bit_le(bit_pos + i, &dentry_blk->dentry_bitmap);
 522        set_page_dirty(dentry_page);
 523
 524        /* we don't need to mark_inode_dirty now */
 525        F2FS_I(inode)->i_pino = dir->i_ino;
 526        update_inode(inode, page);
 527        f2fs_put_page(page, 1);
 528
 529        update_parent_metadata(dir, inode, current_depth);
 530fail:
 531        up_write(&F2FS_I(inode)->i_sem);
 532
 533        if (is_inode_flag_set(F2FS_I(dir), FI_UPDATE_DIR)) {
 534                update_inode_page(dir);
 535                clear_inode_flag(F2FS_I(dir), FI_UPDATE_DIR);
 536        }
 537        kunmap(dentry_page);
 538        f2fs_put_page(dentry_page, 1);
 539        return err;
 540}
 541
 542int f2fs_do_tmpfile(struct inode *inode, struct inode *dir)
 543{
 544        struct page *page;
 545        int err = 0;
 546
 547        down_write(&F2FS_I(inode)->i_sem);
 548        page = init_inode_metadata(inode, dir, NULL);
 549        if (IS_ERR(page)) {
 550                err = PTR_ERR(page);
 551                goto fail;
 552        }
 553        /* we don't need to mark_inode_dirty now */
 554        update_inode(inode, page);
 555        f2fs_put_page(page, 1);
 556
 557        clear_inode_flag(F2FS_I(inode), FI_NEW_INODE);
 558fail:
 559        up_write(&F2FS_I(inode)->i_sem);
 560        return err;
 561}
 562
 563/*
 564 * It only removes the dentry from the dentry page, corresponding name
 565 * entry in name page does not need to be touched during deletion.
 566 */
 567void f2fs_delete_entry(struct f2fs_dir_entry *dentry, struct page *page,
 568                                                struct inode *inode)
 569{
 570        struct  f2fs_dentry_block *dentry_blk;
 571        unsigned int bit_pos;
 572        struct inode *dir = page->mapping->host;
 573        int slots = GET_DENTRY_SLOTS(le16_to_cpu(dentry->name_len));
 574        int i;
 575
 576        lock_page(page);
 577        f2fs_wait_on_page_writeback(page, DATA);
 578
 579        dentry_blk = page_address(page);
 580        bit_pos = dentry - dentry_blk->dentry;
 581        for (i = 0; i < slots; i++)
 582                test_and_clear_bit_le(bit_pos + i, &dentry_blk->dentry_bitmap);
 583
 584        /* Let's check and deallocate this dentry page */
 585        bit_pos = find_next_bit_le(&dentry_blk->dentry_bitmap,
 586                        NR_DENTRY_IN_BLOCK,
 587                        0);
 588        kunmap(page); /* kunmap - pair of f2fs_find_entry */
 589        set_page_dirty(page);
 590
 591        dir->i_ctime = dir->i_mtime = CURRENT_TIME;
 592
 593        if (inode) {
 594                struct f2fs_sb_info *sbi = F2FS_I_SB(dir);
 595
 596                down_write(&F2FS_I(inode)->i_sem);
 597
 598                if (S_ISDIR(inode->i_mode)) {
 599                        drop_nlink(dir);
 600                        update_inode_page(dir);
 601                }
 602                inode->i_ctime = CURRENT_TIME;
 603                drop_nlink(inode);
 604                if (S_ISDIR(inode->i_mode)) {
 605                        drop_nlink(inode);
 606                        i_size_write(inode, 0);
 607                }
 608                up_write(&F2FS_I(inode)->i_sem);
 609                update_inode_page(inode);
 610
 611                if (inode->i_nlink == 0)
 612                        add_orphan_inode(sbi, inode->i_ino);
 613                else
 614                        release_orphan_inode(sbi);
 615        }
 616
 617        if (bit_pos == NR_DENTRY_IN_BLOCK) {
 618                truncate_hole(dir, page->index, page->index + 1);
 619                clear_page_dirty_for_io(page);
 620                ClearPageUptodate(page);
 621                inode_dec_dirty_pages(dir);
 622        }
 623        f2fs_put_page(page, 1);
 624}
 625
 626bool f2fs_empty_dir(struct inode *dir)
 627{
 628        unsigned long bidx;
 629        struct page *dentry_page;
 630        unsigned int bit_pos;
 631        struct  f2fs_dentry_block *dentry_blk;
 632        unsigned long nblock = dir_blocks(dir);
 633
 634        for (bidx = 0; bidx < nblock; bidx++) {
 635                dentry_page = get_lock_data_page(dir, bidx);
 636                if (IS_ERR(dentry_page)) {
 637                        if (PTR_ERR(dentry_page) == -ENOENT)
 638                                continue;
 639                        else
 640                                return false;
 641                }
 642
 643
 644                dentry_blk = kmap_atomic(dentry_page);
 645                if (bidx == 0)
 646                        bit_pos = 2;
 647                else
 648                        bit_pos = 0;
 649                bit_pos = find_next_bit_le(&dentry_blk->dentry_bitmap,
 650                                                NR_DENTRY_IN_BLOCK,
 651                                                bit_pos);
 652                kunmap_atomic(dentry_blk);
 653
 654                f2fs_put_page(dentry_page, 1);
 655
 656                if (bit_pos < NR_DENTRY_IN_BLOCK)
 657                        return false;
 658        }
 659        return true;
 660}
 661
 662static int f2fs_readdir(struct file *file, struct dir_context *ctx)
 663{
 664        struct inode *inode = file_inode(file);
 665        unsigned long npages = dir_blocks(inode);
 666        unsigned int bit_pos = 0;
 667        struct f2fs_dentry_block *dentry_blk = NULL;
 668        struct f2fs_dir_entry *de = NULL;
 669        struct page *dentry_page = NULL;
 670        struct file_ra_state *ra = &file->f_ra;
 671        unsigned int n = ((unsigned long)ctx->pos / NR_DENTRY_IN_BLOCK);
 672        unsigned char d_type = DT_UNKNOWN;
 673
 674        bit_pos = ((unsigned long)ctx->pos % NR_DENTRY_IN_BLOCK);
 675
 676        /* readahead for multi pages of dir */
 677        if (npages - n > 1 && !ra_has_index(ra, n))
 678                page_cache_sync_readahead(inode->i_mapping, ra, file, n,
 679                                min(npages - n, (pgoff_t)MAX_DIR_RA_PAGES));
 680
 681        for (; n < npages; n++) {
 682                dentry_page = get_lock_data_page(inode, n);
 683                if (IS_ERR(dentry_page))
 684                        continue;
 685
 686                dentry_blk = kmap(dentry_page);
 687                while (bit_pos < NR_DENTRY_IN_BLOCK) {
 688                        bit_pos = find_next_bit_le(&dentry_blk->dentry_bitmap,
 689                                                        NR_DENTRY_IN_BLOCK,
 690                                                        bit_pos);
 691                        if (bit_pos >= NR_DENTRY_IN_BLOCK)
 692                                break;
 693
 694                        de = &dentry_blk->dentry[bit_pos];
 695                        if (de->file_type < F2FS_FT_MAX)
 696                                d_type = f2fs_filetype_table[de->file_type];
 697                        else
 698                                d_type = DT_UNKNOWN;
 699                        if (!dir_emit(ctx,
 700                                        dentry_blk->filename[bit_pos],
 701                                        le16_to_cpu(de->name_len),
 702                                        le32_to_cpu(de->ino), d_type))
 703                                goto stop;
 704
 705                        bit_pos += GET_DENTRY_SLOTS(le16_to_cpu(de->name_len));
 706                        ctx->pos = n * NR_DENTRY_IN_BLOCK + bit_pos;
 707                }
 708                bit_pos = 0;
 709                ctx->pos = (n + 1) * NR_DENTRY_IN_BLOCK;
 710                kunmap(dentry_page);
 711                f2fs_put_page(dentry_page, 1);
 712                dentry_page = NULL;
 713        }
 714stop:
 715        if (dentry_page && !IS_ERR(dentry_page)) {
 716                kunmap(dentry_page);
 717                f2fs_put_page(dentry_page, 1);
 718        }
 719
 720        return 0;
 721}
 722
 723const struct file_operations f2fs_dir_operations = {
 724        .llseek         = generic_file_llseek,
 725        .read           = generic_read_dir,
 726        .iterate        = f2fs_readdir,
 727        .fsync          = f2fs_sync_file,
 728        .unlocked_ioctl = f2fs_ioctl,
 729};
 730