root/fs/f2fs/dir.c

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DEFINITIONS

This source file includes following definitions.
  1. dir_blocks
  2. dir_buckets
  3. bucket_blocks
  4. set_de_type
  5. f2fs_get_de_type
  6. dir_block_index
  7. find_in_block
  8. f2fs_ci_compare
  9. f2fs_fname_setup_ci_filename
  10. f2fs_match_name
  11. f2fs_find_target_dentry
  12. find_in_level
  13. __f2fs_find_entry
  14. f2fs_find_entry
  15. f2fs_parent_dir
  16. f2fs_inode_by_name
  17. f2fs_set_link
  18. init_dent_inode
  19. f2fs_do_make_empty_dir
  20. make_empty_dir
  21. f2fs_init_inode_metadata
  22. f2fs_update_parent_metadata
  23. f2fs_room_for_filename
  24. f2fs_update_dentry
  25. f2fs_add_regular_entry
  26. f2fs_add_dentry
  27. f2fs_do_add_link
  28. f2fs_do_tmpfile
  29. f2fs_drop_nlink
  30. f2fs_delete_entry
  31. f2fs_empty_dir
  32. f2fs_fill_dentries
  33. f2fs_readdir
  34. f2fs_dir_open
  35. f2fs_d_compare
  36. f2fs_d_hash

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * fs/f2fs/dir.c
   4  *
   5  * Copyright (c) 2012 Samsung Electronics Co., Ltd.
   6  *             http://www.samsung.com/
   7  */
   8 #include <linux/fs.h>
   9 #include <linux/f2fs_fs.h>
  10 #include <linux/sched/signal.h>
  11 #include <linux/unicode.h>
  12 #include "f2fs.h"
  13 #include "node.h"
  14 #include "acl.h"
  15 #include "xattr.h"
  16 #include <trace/events/f2fs.h>
  17 
  18 static unsigned long dir_blocks(struct inode *inode)
  19 {
  20         return ((unsigned long long) (i_size_read(inode) + PAGE_SIZE - 1))
  21                                                         >> PAGE_SHIFT;
  22 }
  23 
  24 static 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 
  32 static 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 
  40 static 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 static unsigned char f2fs_type_by_mode[S_IFMT >> S_SHIFT] = {
  52         [S_IFREG >> S_SHIFT]    = F2FS_FT_REG_FILE,
  53         [S_IFDIR >> S_SHIFT]    = F2FS_FT_DIR,
  54         [S_IFCHR >> S_SHIFT]    = F2FS_FT_CHRDEV,
  55         [S_IFBLK >> S_SHIFT]    = F2FS_FT_BLKDEV,
  56         [S_IFIFO >> S_SHIFT]    = F2FS_FT_FIFO,
  57         [S_IFSOCK >> S_SHIFT]   = F2FS_FT_SOCK,
  58         [S_IFLNK >> S_SHIFT]    = F2FS_FT_SYMLINK,
  59 };
  60 
  61 static void set_de_type(struct f2fs_dir_entry *de, umode_t mode)
  62 {
  63         de->file_type = f2fs_type_by_mode[(mode & S_IFMT) >> S_SHIFT];
  64 }
  65 
  66 unsigned char f2fs_get_de_type(struct f2fs_dir_entry *de)
  67 {
  68         if (de->file_type < F2FS_FT_MAX)
  69                 return f2fs_filetype_table[de->file_type];
  70         return DT_UNKNOWN;
  71 }
  72 
  73 static unsigned long dir_block_index(unsigned int level,
  74                                 int dir_level, unsigned int idx)
  75 {
  76         unsigned long i;
  77         unsigned long bidx = 0;
  78 
  79         for (i = 0; i < level; i++)
  80                 bidx += dir_buckets(i, dir_level) * bucket_blocks(i);
  81         bidx += idx * bucket_blocks(level);
  82         return bidx;
  83 }
  84 
  85 static struct f2fs_dir_entry *find_in_block(struct inode *dir,
  86                                 struct page *dentry_page,
  87                                 struct fscrypt_name *fname,
  88                                 f2fs_hash_t namehash,
  89                                 int *max_slots,
  90                                 struct page **res_page)
  91 {
  92         struct f2fs_dentry_block *dentry_blk;
  93         struct f2fs_dir_entry *de;
  94         struct f2fs_dentry_ptr d;
  95 
  96         dentry_blk = (struct f2fs_dentry_block *)page_address(dentry_page);
  97 
  98         make_dentry_ptr_block(dir, &d, dentry_blk);
  99         de = f2fs_find_target_dentry(fname, namehash, max_slots, &d);
 100         if (de)
 101                 *res_page = dentry_page;
 102 
 103         return de;
 104 }
 105 
 106 #ifdef CONFIG_UNICODE
 107 /*
 108  * Test whether a case-insensitive directory entry matches the filename
 109  * being searched for.
 110  *
 111  * Returns: 0 if the directory entry matches, more than 0 if it
 112  * doesn't match or less than zero on error.
 113  */
 114 int f2fs_ci_compare(const struct inode *parent, const struct qstr *name,
 115                                 const struct qstr *entry, bool quick)
 116 {
 117         const struct f2fs_sb_info *sbi = F2FS_SB(parent->i_sb);
 118         const struct unicode_map *um = sbi->s_encoding;
 119         int ret;
 120 
 121         if (quick)
 122                 ret = utf8_strncasecmp_folded(um, name, entry);
 123         else
 124                 ret = utf8_strncasecmp(um, name, entry);
 125 
 126         if (ret < 0) {
 127                 /* Handle invalid character sequence as either an error
 128                  * or as an opaque byte sequence.
 129                  */
 130                 if (f2fs_has_strict_mode(sbi))
 131                         return -EINVAL;
 132 
 133                 if (name->len != entry->len)
 134                         return 1;
 135 
 136                 return !!memcmp(name->name, entry->name, name->len);
 137         }
 138 
 139         return ret;
 140 }
 141 
 142 static void f2fs_fname_setup_ci_filename(struct inode *dir,
 143                                         const struct qstr *iname,
 144                                         struct fscrypt_str *cf_name)
 145 {
 146         struct f2fs_sb_info *sbi = F2FS_I_SB(dir);
 147 
 148         if (!IS_CASEFOLDED(dir)) {
 149                 cf_name->name = NULL;
 150                 return;
 151         }
 152 
 153         cf_name->name = f2fs_kmalloc(sbi, F2FS_NAME_LEN, GFP_NOFS);
 154         if (!cf_name->name)
 155                 return;
 156 
 157         cf_name->len = utf8_casefold(sbi->s_encoding,
 158                                         iname, cf_name->name,
 159                                         F2FS_NAME_LEN);
 160         if ((int)cf_name->len <= 0) {
 161                 kvfree(cf_name->name);
 162                 cf_name->name = NULL;
 163         }
 164 }
 165 #endif
 166 
 167 static inline bool f2fs_match_name(struct f2fs_dentry_ptr *d,
 168                                         struct f2fs_dir_entry *de,
 169                                         struct fscrypt_name *fname,
 170                                         struct fscrypt_str *cf_str,
 171                                         unsigned long bit_pos,
 172                                         f2fs_hash_t namehash)
 173 {
 174 #ifdef CONFIG_UNICODE
 175         struct inode *parent = d->inode;
 176         struct f2fs_sb_info *sbi = F2FS_I_SB(parent);
 177         struct qstr entry;
 178 #endif
 179 
 180         if (de->hash_code != namehash)
 181                 return false;
 182 
 183 #ifdef CONFIG_UNICODE
 184         entry.name = d->filename[bit_pos];
 185         entry.len = de->name_len;
 186 
 187         if (sbi->s_encoding && IS_CASEFOLDED(parent)) {
 188                 if (cf_str->name) {
 189                         struct qstr cf = {.name = cf_str->name,
 190                                           .len = cf_str->len};
 191                         return !f2fs_ci_compare(parent, &cf, &entry, true);
 192                 }
 193                 return !f2fs_ci_compare(parent, fname->usr_fname, &entry,
 194                                         false);
 195         }
 196 #endif
 197         if (fscrypt_match_name(fname, d->filename[bit_pos],
 198                                 le16_to_cpu(de->name_len)))
 199                 return true;
 200         return false;
 201 }
 202 
 203 struct f2fs_dir_entry *f2fs_find_target_dentry(struct fscrypt_name *fname,
 204                         f2fs_hash_t namehash, int *max_slots,
 205                         struct f2fs_dentry_ptr *d)
 206 {
 207         struct f2fs_dir_entry *de;
 208         struct fscrypt_str cf_str = { .name = NULL, .len = 0 };
 209         unsigned long bit_pos = 0;
 210         int max_len = 0;
 211 
 212 #ifdef CONFIG_UNICODE
 213         f2fs_fname_setup_ci_filename(d->inode, fname->usr_fname, &cf_str);
 214 #endif
 215 
 216         if (max_slots)
 217                 *max_slots = 0;
 218         while (bit_pos < d->max) {
 219                 if (!test_bit_le(bit_pos, d->bitmap)) {
 220                         bit_pos++;
 221                         max_len++;
 222                         continue;
 223                 }
 224 
 225                 de = &d->dentry[bit_pos];
 226 
 227                 if (unlikely(!de->name_len)) {
 228                         bit_pos++;
 229                         continue;
 230                 }
 231 
 232                 if (f2fs_match_name(d, de, fname, &cf_str, bit_pos, namehash))
 233                         goto found;
 234 
 235                 if (max_slots && max_len > *max_slots)
 236                         *max_slots = max_len;
 237                 max_len = 0;
 238 
 239                 bit_pos += GET_DENTRY_SLOTS(le16_to_cpu(de->name_len));
 240         }
 241 
 242         de = NULL;
 243 found:
 244         if (max_slots && max_len > *max_slots)
 245                 *max_slots = max_len;
 246 
 247 #ifdef CONFIG_UNICODE
 248         kvfree(cf_str.name);
 249 #endif
 250         return de;
 251 }
 252 
 253 static struct f2fs_dir_entry *find_in_level(struct inode *dir,
 254                                         unsigned int level,
 255                                         struct fscrypt_name *fname,
 256                                         struct page **res_page)
 257 {
 258         struct qstr name = FSTR_TO_QSTR(&fname->disk_name);
 259         int s = GET_DENTRY_SLOTS(name.len);
 260         unsigned int nbucket, nblock;
 261         unsigned int bidx, end_block;
 262         struct page *dentry_page;
 263         struct f2fs_dir_entry *de = NULL;
 264         bool room = false;
 265         int max_slots;
 266         f2fs_hash_t namehash = f2fs_dentry_hash(dir, &name, fname);
 267 
 268         nbucket = dir_buckets(level, F2FS_I(dir)->i_dir_level);
 269         nblock = bucket_blocks(level);
 270 
 271         bidx = dir_block_index(level, F2FS_I(dir)->i_dir_level,
 272                                         le32_to_cpu(namehash) % nbucket);
 273         end_block = bidx + nblock;
 274 
 275         for (; bidx < end_block; bidx++) {
 276                 /* no need to allocate new dentry pages to all the indices */
 277                 dentry_page = f2fs_find_data_page(dir, bidx);
 278                 if (IS_ERR(dentry_page)) {
 279                         if (PTR_ERR(dentry_page) == -ENOENT) {
 280                                 room = true;
 281                                 continue;
 282                         } else {
 283                                 *res_page = dentry_page;
 284                                 break;
 285                         }
 286                 }
 287 
 288                 de = find_in_block(dir, dentry_page, fname, namehash,
 289                                                         &max_slots, res_page);
 290                 if (de)
 291                         break;
 292 
 293                 if (max_slots >= s)
 294                         room = true;
 295                 f2fs_put_page(dentry_page, 0);
 296         }
 297 
 298         if (!de && room && F2FS_I(dir)->chash != namehash) {
 299                 F2FS_I(dir)->chash = namehash;
 300                 F2FS_I(dir)->clevel = level;
 301         }
 302 
 303         return de;
 304 }
 305 
 306 struct f2fs_dir_entry *__f2fs_find_entry(struct inode *dir,
 307                         struct fscrypt_name *fname, struct page **res_page)
 308 {
 309         unsigned long npages = dir_blocks(dir);
 310         struct f2fs_dir_entry *de = NULL;
 311         unsigned int max_depth;
 312         unsigned int level;
 313 
 314         if (f2fs_has_inline_dentry(dir)) {
 315                 *res_page = NULL;
 316                 de = f2fs_find_in_inline_dir(dir, fname, res_page);
 317                 goto out;
 318         }
 319 
 320         if (npages == 0) {
 321                 *res_page = NULL;
 322                 goto out;
 323         }
 324 
 325         max_depth = F2FS_I(dir)->i_current_depth;
 326         if (unlikely(max_depth > MAX_DIR_HASH_DEPTH)) {
 327                 f2fs_warn(F2FS_I_SB(dir), "Corrupted max_depth of %lu: %u",
 328                           dir->i_ino, max_depth);
 329                 max_depth = MAX_DIR_HASH_DEPTH;
 330                 f2fs_i_depth_write(dir, max_depth);
 331         }
 332 
 333         for (level = 0; level < max_depth; level++) {
 334                 *res_page = NULL;
 335                 de = find_in_level(dir, level, fname, res_page);
 336                 if (de || IS_ERR(*res_page))
 337                         break;
 338         }
 339 out:
 340         /* This is to increase the speed of f2fs_create */
 341         if (!de)
 342                 F2FS_I(dir)->task = current;
 343         return de;
 344 }
 345 
 346 /*
 347  * Find an entry in the specified directory with the wanted name.
 348  * It returns the page where the entry was found (as a parameter - res_page),
 349  * and the entry itself. Page is returned mapped and unlocked.
 350  * Entry is guaranteed to be valid.
 351  */
 352 struct f2fs_dir_entry *f2fs_find_entry(struct inode *dir,
 353                         const struct qstr *child, struct page **res_page)
 354 {
 355         struct f2fs_dir_entry *de = NULL;
 356         struct fscrypt_name fname;
 357         int err;
 358 
 359 #ifdef CONFIG_UNICODE
 360         if (f2fs_has_strict_mode(F2FS_I_SB(dir)) && IS_CASEFOLDED(dir) &&
 361                         utf8_validate(F2FS_I_SB(dir)->s_encoding, child)) {
 362                 *res_page = ERR_PTR(-EINVAL);
 363                 return NULL;
 364         }
 365 #endif
 366 
 367         err = fscrypt_setup_filename(dir, child, 1, &fname);
 368         if (err) {
 369                 if (err == -ENOENT)
 370                         *res_page = NULL;
 371                 else
 372                         *res_page = ERR_PTR(err);
 373                 return NULL;
 374         }
 375 
 376         de = __f2fs_find_entry(dir, &fname, res_page);
 377 
 378         fscrypt_free_filename(&fname);
 379         return de;
 380 }
 381 
 382 struct f2fs_dir_entry *f2fs_parent_dir(struct inode *dir, struct page **p)
 383 {
 384         struct qstr dotdot = QSTR_INIT("..", 2);
 385 
 386         return f2fs_find_entry(dir, &dotdot, p);
 387 }
 388 
 389 ino_t f2fs_inode_by_name(struct inode *dir, const struct qstr *qstr,
 390                                                         struct page **page)
 391 {
 392         ino_t res = 0;
 393         struct f2fs_dir_entry *de;
 394 
 395         de = f2fs_find_entry(dir, qstr, page);
 396         if (de) {
 397                 res = le32_to_cpu(de->ino);
 398                 f2fs_put_page(*page, 0);
 399         }
 400 
 401         return res;
 402 }
 403 
 404 void f2fs_set_link(struct inode *dir, struct f2fs_dir_entry *de,
 405                 struct page *page, struct inode *inode)
 406 {
 407         enum page_type type = f2fs_has_inline_dentry(dir) ? NODE : DATA;
 408         lock_page(page);
 409         f2fs_wait_on_page_writeback(page, type, true, true);
 410         de->ino = cpu_to_le32(inode->i_ino);
 411         set_de_type(de, inode->i_mode);
 412         set_page_dirty(page);
 413 
 414         dir->i_mtime = dir->i_ctime = current_time(dir);
 415         f2fs_mark_inode_dirty_sync(dir, false);
 416         f2fs_put_page(page, 1);
 417 }
 418 
 419 static void init_dent_inode(const struct qstr *name, struct page *ipage)
 420 {
 421         struct f2fs_inode *ri;
 422 
 423         f2fs_wait_on_page_writeback(ipage, NODE, true, true);
 424 
 425         /* copy name info. to this inode page */
 426         ri = F2FS_INODE(ipage);
 427         ri->i_namelen = cpu_to_le32(name->len);
 428         memcpy(ri->i_name, name->name, name->len);
 429         set_page_dirty(ipage);
 430 }
 431 
 432 void f2fs_do_make_empty_dir(struct inode *inode, struct inode *parent,
 433                                         struct f2fs_dentry_ptr *d)
 434 {
 435         struct qstr dot = QSTR_INIT(".", 1);
 436         struct qstr dotdot = QSTR_INIT("..", 2);
 437 
 438         /* update dirent of "." */
 439         f2fs_update_dentry(inode->i_ino, inode->i_mode, d, &dot, 0, 0);
 440 
 441         /* update dirent of ".." */
 442         f2fs_update_dentry(parent->i_ino, parent->i_mode, d, &dotdot, 0, 1);
 443 }
 444 
 445 static int make_empty_dir(struct inode *inode,
 446                 struct inode *parent, struct page *page)
 447 {
 448         struct page *dentry_page;
 449         struct f2fs_dentry_block *dentry_blk;
 450         struct f2fs_dentry_ptr d;
 451 
 452         if (f2fs_has_inline_dentry(inode))
 453                 return f2fs_make_empty_inline_dir(inode, parent, page);
 454 
 455         dentry_page = f2fs_get_new_data_page(inode, page, 0, true);
 456         if (IS_ERR(dentry_page))
 457                 return PTR_ERR(dentry_page);
 458 
 459         dentry_blk = page_address(dentry_page);
 460 
 461         make_dentry_ptr_block(NULL, &d, dentry_blk);
 462         f2fs_do_make_empty_dir(inode, parent, &d);
 463 
 464         set_page_dirty(dentry_page);
 465         f2fs_put_page(dentry_page, 1);
 466         return 0;
 467 }
 468 
 469 struct page *f2fs_init_inode_metadata(struct inode *inode, struct inode *dir,
 470                         const struct qstr *new_name, const struct qstr *orig_name,
 471                         struct page *dpage)
 472 {
 473         struct page *page;
 474         int dummy_encrypt = DUMMY_ENCRYPTION_ENABLED(F2FS_I_SB(dir));
 475         int err;
 476 
 477         if (is_inode_flag_set(inode, FI_NEW_INODE)) {
 478                 page = f2fs_new_inode_page(inode);
 479                 if (IS_ERR(page))
 480                         return page;
 481 
 482                 if (S_ISDIR(inode->i_mode)) {
 483                         /* in order to handle error case */
 484                         get_page(page);
 485                         err = make_empty_dir(inode, dir, page);
 486                         if (err) {
 487                                 lock_page(page);
 488                                 goto put_error;
 489                         }
 490                         put_page(page);
 491                 }
 492 
 493                 err = f2fs_init_acl(inode, dir, page, dpage);
 494                 if (err)
 495                         goto put_error;
 496 
 497                 err = f2fs_init_security(inode, dir, orig_name, page);
 498                 if (err)
 499                         goto put_error;
 500 
 501                 if ((IS_ENCRYPTED(dir) || dummy_encrypt) &&
 502                                         f2fs_may_encrypt(inode)) {
 503                         err = fscrypt_inherit_context(dir, inode, page, false);
 504                         if (err)
 505                                 goto put_error;
 506                 }
 507         } else {
 508                 page = f2fs_get_node_page(F2FS_I_SB(dir), inode->i_ino);
 509                 if (IS_ERR(page))
 510                         return page;
 511         }
 512 
 513         if (new_name) {
 514                 init_dent_inode(new_name, page);
 515                 if (IS_ENCRYPTED(dir))
 516                         file_set_enc_name(inode);
 517         }
 518 
 519         /*
 520          * This file should be checkpointed during fsync.
 521          * We lost i_pino from now on.
 522          */
 523         if (is_inode_flag_set(inode, FI_INC_LINK)) {
 524                 if (!S_ISDIR(inode->i_mode))
 525                         file_lost_pino(inode);
 526                 /*
 527                  * If link the tmpfile to alias through linkat path,
 528                  * we should remove this inode from orphan list.
 529                  */
 530                 if (inode->i_nlink == 0)
 531                         f2fs_remove_orphan_inode(F2FS_I_SB(dir), inode->i_ino);
 532                 f2fs_i_links_write(inode, true);
 533         }
 534         return page;
 535 
 536 put_error:
 537         clear_nlink(inode);
 538         f2fs_update_inode(inode, page);
 539         f2fs_put_page(page, 1);
 540         return ERR_PTR(err);
 541 }
 542 
 543 void f2fs_update_parent_metadata(struct inode *dir, struct inode *inode,
 544                                                 unsigned int current_depth)
 545 {
 546         if (inode && is_inode_flag_set(inode, FI_NEW_INODE)) {
 547                 if (S_ISDIR(inode->i_mode))
 548                         f2fs_i_links_write(dir, true);
 549                 clear_inode_flag(inode, FI_NEW_INODE);
 550         }
 551         dir->i_mtime = dir->i_ctime = current_time(dir);
 552         f2fs_mark_inode_dirty_sync(dir, false);
 553 
 554         if (F2FS_I(dir)->i_current_depth != current_depth)
 555                 f2fs_i_depth_write(dir, current_depth);
 556 
 557         if (inode && is_inode_flag_set(inode, FI_INC_LINK))
 558                 clear_inode_flag(inode, FI_INC_LINK);
 559 }
 560 
 561 int f2fs_room_for_filename(const void *bitmap, int slots, int max_slots)
 562 {
 563         int bit_start = 0;
 564         int zero_start, zero_end;
 565 next:
 566         zero_start = find_next_zero_bit_le(bitmap, max_slots, bit_start);
 567         if (zero_start >= max_slots)
 568                 return max_slots;
 569 
 570         zero_end = find_next_bit_le(bitmap, max_slots, zero_start);
 571         if (zero_end - zero_start >= slots)
 572                 return zero_start;
 573 
 574         bit_start = zero_end + 1;
 575 
 576         if (zero_end + 1 >= max_slots)
 577                 return max_slots;
 578         goto next;
 579 }
 580 
 581 void f2fs_update_dentry(nid_t ino, umode_t mode, struct f2fs_dentry_ptr *d,
 582                                 const struct qstr *name, f2fs_hash_t name_hash,
 583                                 unsigned int bit_pos)
 584 {
 585         struct f2fs_dir_entry *de;
 586         int slots = GET_DENTRY_SLOTS(name->len);
 587         int i;
 588 
 589         de = &d->dentry[bit_pos];
 590         de->hash_code = name_hash;
 591         de->name_len = cpu_to_le16(name->len);
 592         memcpy(d->filename[bit_pos], name->name, name->len);
 593         de->ino = cpu_to_le32(ino);
 594         set_de_type(de, mode);
 595         for (i = 0; i < slots; i++) {
 596                 __set_bit_le(bit_pos + i, (void *)d->bitmap);
 597                 /* avoid wrong garbage data for readdir */
 598                 if (i)
 599                         (de + i)->name_len = 0;
 600         }
 601 }
 602 
 603 int f2fs_add_regular_entry(struct inode *dir, const struct qstr *new_name,
 604                                 const struct qstr *orig_name,
 605                                 struct inode *inode, nid_t ino, umode_t mode)
 606 {
 607         unsigned int bit_pos;
 608         unsigned int level;
 609         unsigned int current_depth;
 610         unsigned long bidx, block;
 611         f2fs_hash_t dentry_hash;
 612         unsigned int nbucket, nblock;
 613         struct page *dentry_page = NULL;
 614         struct f2fs_dentry_block *dentry_blk = NULL;
 615         struct f2fs_dentry_ptr d;
 616         struct page *page = NULL;
 617         int slots, err = 0;
 618 
 619         level = 0;
 620         slots = GET_DENTRY_SLOTS(new_name->len);
 621         dentry_hash = f2fs_dentry_hash(dir, new_name, NULL);
 622 
 623         current_depth = F2FS_I(dir)->i_current_depth;
 624         if (F2FS_I(dir)->chash == dentry_hash) {
 625                 level = F2FS_I(dir)->clevel;
 626                 F2FS_I(dir)->chash = 0;
 627         }
 628 
 629 start:
 630         if (time_to_inject(F2FS_I_SB(dir), FAULT_DIR_DEPTH)) {
 631                 f2fs_show_injection_info(FAULT_DIR_DEPTH);
 632                 return -ENOSPC;
 633         }
 634 
 635         if (unlikely(current_depth == MAX_DIR_HASH_DEPTH))
 636                 return -ENOSPC;
 637 
 638         /* Increase the depth, if required */
 639         if (level == current_depth)
 640                 ++current_depth;
 641 
 642         nbucket = dir_buckets(level, F2FS_I(dir)->i_dir_level);
 643         nblock = bucket_blocks(level);
 644 
 645         bidx = dir_block_index(level, F2FS_I(dir)->i_dir_level,
 646                                 (le32_to_cpu(dentry_hash) % nbucket));
 647 
 648         for (block = bidx; block <= (bidx + nblock - 1); block++) {
 649                 dentry_page = f2fs_get_new_data_page(dir, NULL, block, true);
 650                 if (IS_ERR(dentry_page))
 651                         return PTR_ERR(dentry_page);
 652 
 653                 dentry_blk = page_address(dentry_page);
 654                 bit_pos = f2fs_room_for_filename(&dentry_blk->dentry_bitmap,
 655                                                 slots, NR_DENTRY_IN_BLOCK);
 656                 if (bit_pos < NR_DENTRY_IN_BLOCK)
 657                         goto add_dentry;
 658 
 659                 f2fs_put_page(dentry_page, 1);
 660         }
 661 
 662         /* Move to next level to find the empty slot for new dentry */
 663         ++level;
 664         goto start;
 665 add_dentry:
 666         f2fs_wait_on_page_writeback(dentry_page, DATA, true, true);
 667 
 668         if (inode) {
 669                 down_write(&F2FS_I(inode)->i_sem);
 670                 page = f2fs_init_inode_metadata(inode, dir, new_name,
 671                                                 orig_name, NULL);
 672                 if (IS_ERR(page)) {
 673                         err = PTR_ERR(page);
 674                         goto fail;
 675                 }
 676         }
 677 
 678         make_dentry_ptr_block(NULL, &d, dentry_blk);
 679         f2fs_update_dentry(ino, mode, &d, new_name, dentry_hash, bit_pos);
 680 
 681         set_page_dirty(dentry_page);
 682 
 683         if (inode) {
 684                 f2fs_i_pino_write(inode, dir->i_ino);
 685 
 686                 /* synchronize inode page's data from inode cache */
 687                 if (is_inode_flag_set(inode, FI_NEW_INODE))
 688                         f2fs_update_inode(inode, page);
 689 
 690                 f2fs_put_page(page, 1);
 691         }
 692 
 693         f2fs_update_parent_metadata(dir, inode, current_depth);
 694 fail:
 695         if (inode)
 696                 up_write(&F2FS_I(inode)->i_sem);
 697 
 698         f2fs_put_page(dentry_page, 1);
 699 
 700         return err;
 701 }
 702 
 703 int f2fs_add_dentry(struct inode *dir, struct fscrypt_name *fname,
 704                                 struct inode *inode, nid_t ino, umode_t mode)
 705 {
 706         struct qstr new_name;
 707         int err = -EAGAIN;
 708 
 709         new_name.name = fname_name(fname);
 710         new_name.len = fname_len(fname);
 711 
 712         if (f2fs_has_inline_dentry(dir))
 713                 err = f2fs_add_inline_entry(dir, &new_name, fname->usr_fname,
 714                                                         inode, ino, mode);
 715         if (err == -EAGAIN)
 716                 err = f2fs_add_regular_entry(dir, &new_name, fname->usr_fname,
 717                                                         inode, ino, mode);
 718 
 719         f2fs_update_time(F2FS_I_SB(dir), REQ_TIME);
 720         return err;
 721 }
 722 
 723 /*
 724  * Caller should grab and release a rwsem by calling f2fs_lock_op() and
 725  * f2fs_unlock_op().
 726  */
 727 int f2fs_do_add_link(struct inode *dir, const struct qstr *name,
 728                                 struct inode *inode, nid_t ino, umode_t mode)
 729 {
 730         struct fscrypt_name fname;
 731         struct page *page = NULL;
 732         struct f2fs_dir_entry *de = NULL;
 733         int err;
 734 
 735         err = fscrypt_setup_filename(dir, name, 0, &fname);
 736         if (err)
 737                 return err;
 738 
 739         /*
 740          * An immature stakable filesystem shows a race condition between lookup
 741          * and create. If we have same task when doing lookup and create, it's
 742          * definitely fine as expected by VFS normally. Otherwise, let's just
 743          * verify on-disk dentry one more time, which guarantees filesystem
 744          * consistency more.
 745          */
 746         if (current != F2FS_I(dir)->task) {
 747                 de = __f2fs_find_entry(dir, &fname, &page);
 748                 F2FS_I(dir)->task = NULL;
 749         }
 750         if (de) {
 751                 f2fs_put_page(page, 0);
 752                 err = -EEXIST;
 753         } else if (IS_ERR(page)) {
 754                 err = PTR_ERR(page);
 755         } else {
 756                 err = f2fs_add_dentry(dir, &fname, inode, ino, mode);
 757         }
 758         fscrypt_free_filename(&fname);
 759         return err;
 760 }
 761 
 762 int f2fs_do_tmpfile(struct inode *inode, struct inode *dir)
 763 {
 764         struct page *page;
 765         int err = 0;
 766 
 767         down_write(&F2FS_I(inode)->i_sem);
 768         page = f2fs_init_inode_metadata(inode, dir, NULL, NULL, NULL);
 769         if (IS_ERR(page)) {
 770                 err = PTR_ERR(page);
 771                 goto fail;
 772         }
 773         f2fs_put_page(page, 1);
 774 
 775         clear_inode_flag(inode, FI_NEW_INODE);
 776         f2fs_update_time(F2FS_I_SB(inode), REQ_TIME);
 777 fail:
 778         up_write(&F2FS_I(inode)->i_sem);
 779         return err;
 780 }
 781 
 782 void f2fs_drop_nlink(struct inode *dir, struct inode *inode)
 783 {
 784         struct f2fs_sb_info *sbi = F2FS_I_SB(dir);
 785 
 786         down_write(&F2FS_I(inode)->i_sem);
 787 
 788         if (S_ISDIR(inode->i_mode))
 789                 f2fs_i_links_write(dir, false);
 790         inode->i_ctime = current_time(inode);
 791 
 792         f2fs_i_links_write(inode, false);
 793         if (S_ISDIR(inode->i_mode)) {
 794                 f2fs_i_links_write(inode, false);
 795                 f2fs_i_size_write(inode, 0);
 796         }
 797         up_write(&F2FS_I(inode)->i_sem);
 798 
 799         if (inode->i_nlink == 0)
 800                 f2fs_add_orphan_inode(inode);
 801         else
 802                 f2fs_release_orphan_inode(sbi);
 803 }
 804 
 805 /*
 806  * It only removes the dentry from the dentry page, corresponding name
 807  * entry in name page does not need to be touched during deletion.
 808  */
 809 void f2fs_delete_entry(struct f2fs_dir_entry *dentry, struct page *page,
 810                                         struct inode *dir, struct inode *inode)
 811 {
 812         struct  f2fs_dentry_block *dentry_blk;
 813         unsigned int bit_pos;
 814         int slots = GET_DENTRY_SLOTS(le16_to_cpu(dentry->name_len));
 815         int i;
 816 
 817         f2fs_update_time(F2FS_I_SB(dir), REQ_TIME);
 818 
 819         if (F2FS_OPTION(F2FS_I_SB(dir)).fsync_mode == FSYNC_MODE_STRICT)
 820                 f2fs_add_ino_entry(F2FS_I_SB(dir), dir->i_ino, TRANS_DIR_INO);
 821 
 822         if (f2fs_has_inline_dentry(dir))
 823                 return f2fs_delete_inline_entry(dentry, page, dir, inode);
 824 
 825         lock_page(page);
 826         f2fs_wait_on_page_writeback(page, DATA, true, true);
 827 
 828         dentry_blk = page_address(page);
 829         bit_pos = dentry - dentry_blk->dentry;
 830         for (i = 0; i < slots; i++)
 831                 __clear_bit_le(bit_pos + i, &dentry_blk->dentry_bitmap);
 832 
 833         /* Let's check and deallocate this dentry page */
 834         bit_pos = find_next_bit_le(&dentry_blk->dentry_bitmap,
 835                         NR_DENTRY_IN_BLOCK,
 836                         0);
 837         set_page_dirty(page);
 838 
 839         dir->i_ctime = dir->i_mtime = current_time(dir);
 840         f2fs_mark_inode_dirty_sync(dir, false);
 841 
 842         if (inode)
 843                 f2fs_drop_nlink(dir, inode);
 844 
 845         if (bit_pos == NR_DENTRY_IN_BLOCK &&
 846                 !f2fs_truncate_hole(dir, page->index, page->index + 1)) {
 847                 f2fs_clear_page_cache_dirty_tag(page);
 848                 clear_page_dirty_for_io(page);
 849                 f2fs_clear_page_private(page);
 850                 ClearPageUptodate(page);
 851                 clear_cold_data(page);
 852                 inode_dec_dirty_pages(dir);
 853                 f2fs_remove_dirty_inode(dir);
 854         }
 855         f2fs_put_page(page, 1);
 856 }
 857 
 858 bool f2fs_empty_dir(struct inode *dir)
 859 {
 860         unsigned long bidx;
 861         struct page *dentry_page;
 862         unsigned int bit_pos;
 863         struct f2fs_dentry_block *dentry_blk;
 864         unsigned long nblock = dir_blocks(dir);
 865 
 866         if (f2fs_has_inline_dentry(dir))
 867                 return f2fs_empty_inline_dir(dir);
 868 
 869         for (bidx = 0; bidx < nblock; bidx++) {
 870                 dentry_page = f2fs_get_lock_data_page(dir, bidx, false);
 871                 if (IS_ERR(dentry_page)) {
 872                         if (PTR_ERR(dentry_page) == -ENOENT)
 873                                 continue;
 874                         else
 875                                 return false;
 876                 }
 877 
 878                 dentry_blk = page_address(dentry_page);
 879                 if (bidx == 0)
 880                         bit_pos = 2;
 881                 else
 882                         bit_pos = 0;
 883                 bit_pos = find_next_bit_le(&dentry_blk->dentry_bitmap,
 884                                                 NR_DENTRY_IN_BLOCK,
 885                                                 bit_pos);
 886 
 887                 f2fs_put_page(dentry_page, 1);
 888 
 889                 if (bit_pos < NR_DENTRY_IN_BLOCK)
 890                         return false;
 891         }
 892         return true;
 893 }
 894 
 895 int f2fs_fill_dentries(struct dir_context *ctx, struct f2fs_dentry_ptr *d,
 896                         unsigned int start_pos, struct fscrypt_str *fstr)
 897 {
 898         unsigned char d_type = DT_UNKNOWN;
 899         unsigned int bit_pos;
 900         struct f2fs_dir_entry *de = NULL;
 901         struct fscrypt_str de_name = FSTR_INIT(NULL, 0);
 902         struct f2fs_sb_info *sbi = F2FS_I_SB(d->inode);
 903         struct blk_plug plug;
 904         bool readdir_ra = sbi->readdir_ra == 1;
 905         int err = 0;
 906 
 907         bit_pos = ((unsigned long)ctx->pos % d->max);
 908 
 909         if (readdir_ra)
 910                 blk_start_plug(&plug);
 911 
 912         while (bit_pos < d->max) {
 913                 bit_pos = find_next_bit_le(d->bitmap, d->max, bit_pos);
 914                 if (bit_pos >= d->max)
 915                         break;
 916 
 917                 de = &d->dentry[bit_pos];
 918                 if (de->name_len == 0) {
 919                         bit_pos++;
 920                         ctx->pos = start_pos + bit_pos;
 921                         printk_ratelimited(
 922                                 "%s, invalid namelen(0), ino:%u, run fsck to fix.",
 923                                 KERN_WARNING, le32_to_cpu(de->ino));
 924                         set_sbi_flag(sbi, SBI_NEED_FSCK);
 925                         continue;
 926                 }
 927 
 928                 d_type = f2fs_get_de_type(de);
 929 
 930                 de_name.name = d->filename[bit_pos];
 931                 de_name.len = le16_to_cpu(de->name_len);
 932 
 933                 /* check memory boundary before moving forward */
 934                 bit_pos += GET_DENTRY_SLOTS(le16_to_cpu(de->name_len));
 935                 if (unlikely(bit_pos > d->max ||
 936                                 le16_to_cpu(de->name_len) > F2FS_NAME_LEN)) {
 937                         f2fs_warn(sbi, "%s: corrupted namelen=%d, run fsck to fix.",
 938                                   __func__, le16_to_cpu(de->name_len));
 939                         set_sbi_flag(sbi, SBI_NEED_FSCK);
 940                         err = -EFSCORRUPTED;
 941                         goto out;
 942                 }
 943 
 944                 if (IS_ENCRYPTED(d->inode)) {
 945                         int save_len = fstr->len;
 946 
 947                         err = fscrypt_fname_disk_to_usr(d->inode,
 948                                                 (u32)le32_to_cpu(de->hash_code),
 949                                                 0, &de_name, fstr);
 950                         if (err)
 951                                 goto out;
 952 
 953                         de_name = *fstr;
 954                         fstr->len = save_len;
 955                 }
 956 
 957                 if (!dir_emit(ctx, de_name.name, de_name.len,
 958                                         le32_to_cpu(de->ino), d_type)) {
 959                         err = 1;
 960                         goto out;
 961                 }
 962 
 963                 if (readdir_ra)
 964                         f2fs_ra_node_page(sbi, le32_to_cpu(de->ino));
 965 
 966                 ctx->pos = start_pos + bit_pos;
 967         }
 968 out:
 969         if (readdir_ra)
 970                 blk_finish_plug(&plug);
 971         return err;
 972 }
 973 
 974 static int f2fs_readdir(struct file *file, struct dir_context *ctx)
 975 {
 976         struct inode *inode = file_inode(file);
 977         unsigned long npages = dir_blocks(inode);
 978         struct f2fs_dentry_block *dentry_blk = NULL;
 979         struct page *dentry_page = NULL;
 980         struct file_ra_state *ra = &file->f_ra;
 981         loff_t start_pos = ctx->pos;
 982         unsigned int n = ((unsigned long)ctx->pos / NR_DENTRY_IN_BLOCK);
 983         struct f2fs_dentry_ptr d;
 984         struct fscrypt_str fstr = FSTR_INIT(NULL, 0);
 985         int err = 0;
 986 
 987         if (IS_ENCRYPTED(inode)) {
 988                 err = fscrypt_get_encryption_info(inode);
 989                 if (err && err != -ENOKEY)
 990                         goto out;
 991 
 992                 err = fscrypt_fname_alloc_buffer(inode, F2FS_NAME_LEN, &fstr);
 993                 if (err < 0)
 994                         goto out;
 995         }
 996 
 997         if (f2fs_has_inline_dentry(inode)) {
 998                 err = f2fs_read_inline_dir(file, ctx, &fstr);
 999                 goto out_free;
1000         }
1001 
1002         for (; n < npages; n++, ctx->pos = n * NR_DENTRY_IN_BLOCK) {
1003 
1004                 /* allow readdir() to be interrupted */
1005                 if (fatal_signal_pending(current)) {
1006                         err = -ERESTARTSYS;
1007                         goto out_free;
1008                 }
1009                 cond_resched();
1010 
1011                 /* readahead for multi pages of dir */
1012                 if (npages - n > 1 && !ra_has_index(ra, n))
1013                         page_cache_sync_readahead(inode->i_mapping, ra, file, n,
1014                                 min(npages - n, (pgoff_t)MAX_DIR_RA_PAGES));
1015 
1016                 dentry_page = f2fs_find_data_page(inode, n);
1017                 if (IS_ERR(dentry_page)) {
1018                         err = PTR_ERR(dentry_page);
1019                         if (err == -ENOENT) {
1020                                 err = 0;
1021                                 continue;
1022                         } else {
1023                                 goto out_free;
1024                         }
1025                 }
1026 
1027                 dentry_blk = page_address(dentry_page);
1028 
1029                 make_dentry_ptr_block(inode, &d, dentry_blk);
1030 
1031                 err = f2fs_fill_dentries(ctx, &d,
1032                                 n * NR_DENTRY_IN_BLOCK, &fstr);
1033                 if (err) {
1034                         f2fs_put_page(dentry_page, 0);
1035                         break;
1036                 }
1037 
1038                 f2fs_put_page(dentry_page, 0);
1039         }
1040 out_free:
1041         fscrypt_fname_free_buffer(&fstr);
1042 out:
1043         trace_f2fs_readdir(inode, start_pos, ctx->pos, err);
1044         return err < 0 ? err : 0;
1045 }
1046 
1047 static int f2fs_dir_open(struct inode *inode, struct file *filp)
1048 {
1049         if (IS_ENCRYPTED(inode))
1050                 return fscrypt_get_encryption_info(inode) ? -EACCES : 0;
1051         return 0;
1052 }
1053 
1054 const struct file_operations f2fs_dir_operations = {
1055         .llseek         = generic_file_llseek,
1056         .read           = generic_read_dir,
1057         .iterate_shared = f2fs_readdir,
1058         .fsync          = f2fs_sync_file,
1059         .open           = f2fs_dir_open,
1060         .unlocked_ioctl = f2fs_ioctl,
1061 #ifdef CONFIG_COMPAT
1062         .compat_ioctl   = f2fs_compat_ioctl,
1063 #endif
1064 };
1065 
1066 #ifdef CONFIG_UNICODE
1067 static int f2fs_d_compare(const struct dentry *dentry, unsigned int len,
1068                           const char *str, const struct qstr *name)
1069 {
1070         struct qstr qstr = {.name = str, .len = len };
1071         const struct dentry *parent = READ_ONCE(dentry->d_parent);
1072         const struct inode *inode = READ_ONCE(parent->d_inode);
1073 
1074         if (!inode || !IS_CASEFOLDED(inode)) {
1075                 if (len != name->len)
1076                         return -1;
1077                 return memcmp(str, name->name, len);
1078         }
1079 
1080         return f2fs_ci_compare(inode, name, &qstr, false);
1081 }
1082 
1083 static int f2fs_d_hash(const struct dentry *dentry, struct qstr *str)
1084 {
1085         struct f2fs_sb_info *sbi = F2FS_SB(dentry->d_sb);
1086         const struct unicode_map *um = sbi->s_encoding;
1087         const struct inode *inode = READ_ONCE(dentry->d_inode);
1088         unsigned char *norm;
1089         int len, ret = 0;
1090 
1091         if (!inode || !IS_CASEFOLDED(inode))
1092                 return 0;
1093 
1094         norm = f2fs_kmalloc(sbi, PATH_MAX, GFP_ATOMIC);
1095         if (!norm)
1096                 return -ENOMEM;
1097 
1098         len = utf8_casefold(um, str, norm, PATH_MAX);
1099         if (len < 0) {
1100                 if (f2fs_has_strict_mode(sbi))
1101                         ret = -EINVAL;
1102                 goto out;
1103         }
1104         str->hash = full_name_hash(dentry, norm, len);
1105 out:
1106         kvfree(norm);
1107         return ret;
1108 }
1109 
1110 const struct dentry_operations f2fs_dentry_ops = {
1111         .d_hash = f2fs_d_hash,
1112         .d_compare = f2fs_d_compare,
1113 };
1114 #endif

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