fs/exfat/namei.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Copyright (C) 2012-2013 Samsung Electronics Co., Ltd.
   4  */
   5
   6 #include <linux/iversion.h>
   7 #include <linux/namei.h>
   8 #include <linux/slab.h>
   9 #include <linux/buffer_head.h>
  10 #include <linux/nls.h>
  11
  12 #include "exfat_raw.h"
  13 #include "exfat_fs.h"
  14
  15 static inline unsigned long exfat_d_version(struct dentry *dentry)
  16 {
  17         return (unsigned long) dentry->d_fsdata;
  18 }
  19
  20 static inline void exfat_d_version_set(struct dentry *dentry,
  21                 unsigned long version)
  22 {
  23         dentry->d_fsdata = (void *) version;
  24 }
  25
  26 /*
  27  * If new entry was created in the parent, it could create the 8.3 alias (the
  28  * shortname of logname).  So, the parent may have the negative-dentry which
  29  * matches the created 8.3 alias.
  30  *
  31  * If it happened, the negative dentry isn't actually negative anymore.  So,
  32  * drop it.
  33  */
  34 static int exfat_d_revalidate(struct dentry *dentry, unsigned int flags)
  35 {
  36         int ret;
  37
  38         if (flags & LOOKUP_RCU)
  39                 return -ECHILD;
  40
  41         /*
  42          * This is not negative dentry. Always valid.
  43          *
  44          * Note, rename() to existing directory entry will have ->d_inode, and
  45          * will use existing name which isn't specified name by user.
  46          *
  47          * We may be able to drop this positive dentry here. But dropping
  48          * positive dentry isn't good idea. So it's unsupported like
  49          * rename("filename", "FILENAME") for now.
  50          */
  51         if (d_really_is_positive(dentry))
  52                 return 1;
  53
  54         /*
  55          * Drop the negative dentry, in order to make sure to use the case
  56          * sensitive name which is specified by user if this is for creation.
  57          */
  58         if (flags & (LOOKUP_CREATE | LOOKUP_RENAME_TARGET))
  59                 return 0;
  60
  61         spin_lock(&dentry->d_lock);
  62         ret = inode_eq_iversion(d_inode(dentry->d_parent),
  63                         exfat_d_version(dentry));
  64         spin_unlock(&dentry->d_lock);
  65         return ret;
  66 }
  67
  68 /* returns the length of a struct qstr, ignoring trailing dots */
  69 static unsigned int exfat_striptail_len(unsigned int len, const char *name)
  70 {
  71         while (len && name[len - 1] == '.')
  72                 len--;
  73         return len;
  74 }
  75
  76 /*
  77  * Compute the hash for the exfat name corresponding to the dentry.  If the name
  78  * is invalid, we leave the hash code unchanged so that the existing dentry can
  79  * be used. The exfat fs routines will return ENOENT or EINVAL as appropriate.
  80  */
  81 static int exfat_d_hash(const struct dentry *dentry, struct qstr *qstr)
  82 {
  83         struct super_block *sb = dentry->d_sb;
  84         struct nls_table *t = EXFAT_SB(sb)->nls_io;
  85         const unsigned char *name = qstr->name;
  86         unsigned int len = exfat_striptail_len(qstr->len, qstr->name);
  87         unsigned long hash = init_name_hash(dentry);
  88         int i, charlen;
  89         wchar_t c;
  90
  91         for (i = 0; i < len; i += charlen) {
  92                 charlen = t->char2uni(&name[i], len - i, &c);
  93                 if (charlen < 0)
  94                         return charlen;
  95                 hash = partial_name_hash(exfat_toupper(sb, c), hash);
  96         }
  97
  98         qstr->hash = end_name_hash(hash);
  99         return 0;
 100 }
 101
 102 static int exfat_d_cmp(const struct dentry *dentry, unsigned int len,
 103                 const char *str, const struct qstr *name)
 104 {
 105         struct super_block *sb = dentry->d_sb;
 106         struct nls_table *t = EXFAT_SB(sb)->nls_io;
 107         unsigned int alen = exfat_striptail_len(name->len, name->name);
 108         unsigned int blen = exfat_striptail_len(len, str);
 109         wchar_t c1, c2;
 110         int charlen, i;
 111
 112         if (alen != blen)
 113                 return 1;
 114
 115         for (i = 0; i < len; i += charlen) {
 116                 charlen = t->char2uni(&name->name[i], alen - i, &c1);
 117                 if (charlen < 0)
 118                         return 1;
 119                 if (charlen != t->char2uni(&str[i], blen - i, &c2))
 120                         return 1;
 121
 122                 if (exfat_toupper(sb, c1) != exfat_toupper(sb, c2))
 123                         return 1;
 124         }
 125
 126         return 0;
 127 }
 128
 129 const struct dentry_operations exfat_dentry_ops = {
 130         .d_revalidate   = exfat_d_revalidate,
 131         .d_hash         = exfat_d_hash,
 132         .d_compare      = exfat_d_cmp,
 133 };
 134
 135 static int exfat_utf8_d_hash(const struct dentry *dentry, struct qstr *qstr)
 136 {
 137         struct super_block *sb = dentry->d_sb;
 138         const unsigned char *name = qstr->name;
 139         unsigned int len = exfat_striptail_len(qstr->len, qstr->name);
 140         unsigned long hash = init_name_hash(dentry);
 141         int i, charlen;
 142         unicode_t u;
 143
 144         for (i = 0; i < len; i += charlen) {
 145                 charlen = utf8_to_utf32(&name[i], len - i, &u);
 146                 if (charlen < 0)
 147                         return charlen;
 148
 149                 /*
 150                  * exfat_toupper() works only for code points up to the U+FFFF.
 151                  */
 152                 hash = partial_name_hash(u <= 0xFFFF ? exfat_toupper(sb, u) : u,
 153                                          hash);
 154         }
 155
 156         qstr->hash = end_name_hash(hash);
 157         return 0;
 158 }
 159
 160 static int exfat_utf8_d_cmp(const struct dentry *dentry, unsigned int len,
 161                 const char *str, const struct qstr *name)
 162 {
 163         struct super_block *sb = dentry->d_sb;
 164         unsigned int alen = exfat_striptail_len(name->len, name->name);
 165         unsigned int blen = exfat_striptail_len(len, str);
 166         unicode_t u_a, u_b;
 167         int charlen, i;
 168
 169         if (alen != blen)
 170                 return 1;
 171
 172         for (i = 0; i < alen; i += charlen) {
 173                 charlen = utf8_to_utf32(&name->name[i], alen - i, &u_a);
 174                 if (charlen < 0)
 175                         return 1;
 176                 if (charlen != utf8_to_utf32(&str[i], blen - i, &u_b))
 177                         return 1;
 178
 179                 if (u_a <= 0xFFFF && u_b <= 0xFFFF) {
 180                         if (exfat_toupper(sb, u_a) != exfat_toupper(sb, u_b))
 181                                 return 1;
 182                 } else {
 183                         if (u_a != u_b)
 184                                 return 1;
 185                 }
 186         }
 187
 188         return 0;
 189 }
 190
 191 const struct dentry_operations exfat_utf8_dentry_ops = {
 192         .d_revalidate   = exfat_d_revalidate,
 193         .d_hash         = exfat_utf8_d_hash,
 194         .d_compare      = exfat_utf8_d_cmp,
 195 };
 196
 197 /* used only in search empty_slot() */
 198 #define CNT_UNUSED_NOHIT        (-1)
 199 #define CNT_UNUSED_HIT          (-2)
 200 /* search EMPTY CONTINUOUS "num_entries" entries */
 201 static int exfat_search_empty_slot(struct super_block *sb,
 202                 struct exfat_hint_femp *hint_femp, struct exfat_chain *p_dir,
 203                 int num_entries)
 204 {
 205         int i, dentry, num_empty = 0;
 206         int dentries_per_clu;
 207         unsigned int type;
 208         struct exfat_chain clu;
 209         struct exfat_dentry *ep;
 210         struct exfat_sb_info *sbi = EXFAT_SB(sb);
 211         struct buffer_head *bh;
 212
 213         dentries_per_clu = sbi->dentries_per_clu;
 214
 215         if (hint_femp->eidx != EXFAT_HINT_NONE) {
 216                 dentry = hint_femp->eidx;
 217                 if (num_entries <= hint_femp->count) {
 218                         hint_femp->eidx = EXFAT_HINT_NONE;
 219                         return dentry;
 220                 }
 221
 222                 exfat_chain_dup(&clu, &hint_femp->cur);
 223         } else {
 224                 exfat_chain_dup(&clu, p_dir);
 225                 dentry = 0;
 226         }
 227
 228         while (clu.dir != EXFAT_EOF_CLUSTER) {
 229                 i = dentry & (dentries_per_clu - 1);
 230
 231                 for (; i < dentries_per_clu; i++, dentry++) {
 232                         ep = exfat_get_dentry(sb, &clu, i, &bh, NULL);
 233                         if (!ep)
 234                                 return -EIO;
 235                         type = exfat_get_entry_type(ep);
 236                         brelse(bh);
 237
 238                         if (type == TYPE_UNUSED || type == TYPE_DELETED) {
 239                                 num_empty++;
 240                                 if (hint_femp->eidx == EXFAT_HINT_NONE) {
 241                                         hint_femp->eidx = dentry;
 242                                         hint_femp->count = CNT_UNUSED_NOHIT;
 243                                         exfat_chain_set(&hint_femp->cur,
 244                                                 clu.dir, clu.size, clu.flags);
 245                                 }
 246
 247                                 if (type == TYPE_UNUSED &&
 248                                     hint_femp->count != CNT_UNUSED_HIT)
 249                                         hint_femp->count = CNT_UNUSED_HIT;
 250                         } else {
 251                                 if (hint_femp->eidx != EXFAT_HINT_NONE &&
 252                                     hint_femp->count == CNT_UNUSED_HIT) {
 253                                         /* unused empty group means
 254                                          * an empty group which includes
 255                                          * unused dentry
 256                                          */
 257                                         exfat_fs_error(sb,
 258                                                 "found bogus dentry(%d) beyond unused empty group(%d) (start_clu : %u, cur_clu : %u)",
 259                                                 dentry, hint_femp->eidx,
 260                                                 p_dir->dir, clu.dir);
 261                                         return -EIO;
 262                                 }
 263
 264                                 num_empty = 0;
 265                                 hint_femp->eidx = EXFAT_HINT_NONE;
 266                         }
 267
 268                         if (num_empty >= num_entries) {
 269                                 /* found and invalidate hint_femp */
 270                                 hint_femp->eidx = EXFAT_HINT_NONE;
 271                                 return (dentry - (num_entries - 1));
 272                         }
 273                 }
 274
 275                 if (clu.flags == ALLOC_NO_FAT_CHAIN) {
 276                         if (--clu.size > 0)
 277                                 clu.dir++;
 278                         else
 279                                 clu.dir = EXFAT_EOF_CLUSTER;
 280                 } else {
 281                         if (exfat_get_next_cluster(sb, &clu.dir))
 282                                 return -EIO;
 283                 }
 284         }
 285
 286         return -ENOSPC;
 287 }
 288
 289 static int exfat_check_max_dentries(struct inode *inode)
 290 {
 291         if (EXFAT_B_TO_DEN(i_size_read(inode)) >= MAX_EXFAT_DENTRIES) {
 292                 /*
 293                  * exFAT spec allows a dir to grow upto 8388608(256MB)
 294                  * dentries
 295                  */
 296                 return -ENOSPC;
 297         }
 298         return 0;
 299 }
 300
 301 /* find empty directory entry.
 302  * if there isn't any empty slot, expand cluster chain.
 303  */
 304 static int exfat_find_empty_entry(struct inode *inode,
 305                 struct exfat_chain *p_dir, int num_entries)
 306 {
 307         int dentry;
 308         unsigned int ret, last_clu;
 309         sector_t sector;
 310         loff_t size = 0;
 311         struct exfat_chain clu;
 312         struct exfat_dentry *ep = NULL;
 313         struct super_block *sb = inode->i_sb;
 314         struct exfat_sb_info *sbi = EXFAT_SB(sb);
 315         struct exfat_inode_info *ei = EXFAT_I(inode);
 316         struct exfat_hint_femp hint_femp;
 317
 318         hint_femp.eidx = EXFAT_HINT_NONE;
 319
 320         if (ei->hint_femp.eidx != EXFAT_HINT_NONE) {
 321                 memcpy(&hint_femp, &ei->hint_femp,
 322                                 sizeof(struct exfat_hint_femp));
 323                 ei->hint_femp.eidx = EXFAT_HINT_NONE;
 324         }
 325
 326         while ((dentry = exfat_search_empty_slot(sb, &hint_femp, p_dir,
 327                                         num_entries)) < 0) {
 328                 if (dentry == -EIO)
 329                         break;
 330
 331                 if (exfat_check_max_dentries(inode))
 332                         return -ENOSPC;
 333
 334                 /* we trust p_dir->size regardless of FAT type */
 335                 if (exfat_find_last_cluster(sb, p_dir, &last_clu))
 336                         return -EIO;
 337
 338                 /*
 339                  * Allocate new cluster to this directory
 340                  */
 341                 exfat_chain_set(&clu, last_clu + 1, 0, p_dir->flags);
 342
 343                 /* allocate a cluster */
 344                 ret = exfat_alloc_cluster(inode, 1, &clu);
 345                 if (ret)
 346                         return ret;
 347
 348                 if (exfat_zeroed_cluster(inode, clu.dir))
 349                         return -EIO;
 350
 351                 /* append to the FAT chain */
 352                 if (clu.flags != p_dir->flags) {
 353                         /* no-fat-chain bit is disabled,
 354                          * so fat-chain should be synced with alloc-bitmap
 355                          */
 356                         exfat_chain_cont_cluster(sb, p_dir->dir, p_dir->size);
 357                         p_dir->flags = ALLOC_FAT_CHAIN;
 358                         hint_femp.cur.flags = ALLOC_FAT_CHAIN;
 359                 }
 360
 361                 if (clu.flags == ALLOC_FAT_CHAIN)
 362                         if (exfat_ent_set(sb, last_clu, clu.dir))
 363                                 return -EIO;
 364
 365                 if (hint_femp.eidx == EXFAT_HINT_NONE) {
 366                         /* the special case that new dentry
 367                          * should be allocated from the start of new cluster
 368                          */
 369                         hint_femp.eidx = EXFAT_B_TO_DEN_IDX(p_dir->size, sbi);
 370                         hint_femp.count = sbi->dentries_per_clu;
 371
 372                         exfat_chain_set(&hint_femp.cur, clu.dir, 0, clu.flags);
 373                 }
 374                 hint_femp.cur.size++;
 375                 p_dir->size++;
 376                 size = EXFAT_CLU_TO_B(p_dir->size, sbi);
 377
 378                 /* update the directory entry */
 379                 if (p_dir->dir != sbi->root_dir) {
 380                         struct buffer_head *bh;
 381
 382                         ep = exfat_get_dentry(sb,
 383                                 &(ei->dir), ei->entry + 1, &bh, &sector);
 384                         if (!ep)
 385                                 return -EIO;
 386
 387                         ep->dentry.stream.valid_size = cpu_to_le64(size);
 388                         ep->dentry.stream.size = ep->dentry.stream.valid_size;
 389                         ep->dentry.stream.flags = p_dir->flags;
 390                         exfat_update_bh(bh, IS_DIRSYNC(inode));
 391                         brelse(bh);
 392                         if (exfat_update_dir_chksum(inode, &(ei->dir),
 393                             ei->entry))
 394                                 return -EIO;
 395                 }
 396
 397                 /* directory inode should be updated in here */
 398                 i_size_write(inode, size);
 399                 EXFAT_I(inode)->i_size_ondisk += sbi->cluster_size;
 400                 EXFAT_I(inode)->i_size_aligned += sbi->cluster_size;
 401                 EXFAT_I(inode)->flags = p_dir->flags;
 402                 inode->i_blocks += 1 << sbi->sect_per_clus_bits;
 403         }
 404
 405         return dentry;
 406 }
 407
 408 /*
 409  * Name Resolution Functions :
 410  * Zero if it was successful; otherwise nonzero.
 411  */
 412 static int __exfat_resolve_path(struct inode *inode, const unsigned char *path,
 413                 struct exfat_chain *p_dir, struct exfat_uni_name *p_uniname,
 414                 int lookup)
 415 {
 416         int namelen;
 417         int lossy = NLS_NAME_NO_LOSSY;
 418         struct super_block *sb = inode->i_sb;
 419         struct exfat_sb_info *sbi = EXFAT_SB(sb);
 420         struct exfat_inode_info *ei = EXFAT_I(inode);
 421
 422         /* strip all trailing periods */
 423         namelen = exfat_striptail_len(strlen(path), path);
 424         if (!namelen)
 425                 return -ENOENT;
 426
 427         if (strlen(path) > (MAX_NAME_LENGTH * MAX_CHARSET_SIZE))
 428                 return -ENAMETOOLONG;
 429
 430         /*
 431          * strip all leading spaces :
 432          * "MS windows 7" supports leading spaces.
 433          * So we should skip this preprocessing for compatibility.
 434          */
 435
 436         /* file name conversion :
 437          * If lookup case, we allow bad-name for compatibility.
 438          */
 439         namelen = exfat_nls_to_utf16(sb, path, namelen, p_uniname,
 440                         &lossy);
 441         if (namelen < 0)
 442                 return namelen; /* return error value */
 443
 444         if ((lossy && !lookup) || !namelen)
 445                 return -EINVAL;
 446
 447         exfat_chain_set(p_dir, ei->start_clu,
 448                 EXFAT_B_TO_CLU(i_size_read(inode), sbi), ei->flags);
 449
 450         return 0;
 451 }
 452
 453 static inline int exfat_resolve_path(struct inode *inode,
 454                 const unsigned char *path, struct exfat_chain *dir,
 455                 struct exfat_uni_name *uni)
 456 {
 457         return __exfat_resolve_path(inode, path, dir, uni, 0);
 458 }
 459
 460 static inline int exfat_resolve_path_for_lookup(struct inode *inode,
 461                 const unsigned char *path, struct exfat_chain *dir,
 462                 struct exfat_uni_name *uni)
 463 {
 464         return __exfat_resolve_path(inode, path, dir, uni, 1);
 465 }
 466
 467 static inline loff_t exfat_make_i_pos(struct exfat_dir_entry *info)
 468 {
 469         return ((loff_t) info->dir.dir << 32) | (info->entry & 0xffffffff);
 470 }
 471
 472 static int exfat_add_entry(struct inode *inode, const char *path,
 473                 struct exfat_chain *p_dir, unsigned int type,
 474                 struct exfat_dir_entry *info)
 475 {
 476         int ret, dentry, num_entries;
 477         struct super_block *sb = inode->i_sb;
 478         struct exfat_sb_info *sbi = EXFAT_SB(sb);
 479         struct exfat_uni_name uniname;
 480         struct exfat_chain clu;
 481         int clu_size = 0;
 482         unsigned int start_clu = EXFAT_FREE_CLUSTER;
 483
 484         ret = exfat_resolve_path(inode, path, p_dir, &uniname);
 485         if (ret)
 486                 goto out;
 487
 488         num_entries = exfat_calc_num_entries(&uniname);
 489         if (num_entries < 0) {
 490                 ret = num_entries;
 491                 goto out;
 492         }
 493
 494         /* exfat_find_empty_entry must be called before alloc_cluster() */
 495         dentry = exfat_find_empty_entry(inode, p_dir, num_entries);
 496         if (dentry < 0) {
 497                 ret = dentry; /* -EIO or -ENOSPC */
 498                 goto out;
 499         }
 500
 501         if (type == TYPE_DIR) {
 502                 ret = exfat_alloc_new_dir(inode, &clu);
 503                 if (ret)
 504                         goto out;
 505                 start_clu = clu.dir;
 506                 clu_size = sbi->cluster_size;
 507         }
 508
 509         /* update the directory entry */
 510         /* fill the dos name directory entry information of the created file.
 511          * the first cluster is not determined yet. (0)
 512          */
 513         ret = exfat_init_dir_entry(inode, p_dir, dentry, type,
 514                 start_clu, clu_size);
 515         if (ret)
 516                 goto out;
 517
 518         ret = exfat_init_ext_entry(inode, p_dir, dentry, num_entries, &uniname);
 519         if (ret)
 520                 goto out;
 521
 522         memcpy(&info->dir, p_dir, sizeof(struct exfat_chain));
 523         info->entry = dentry;
 524         info->flags = ALLOC_NO_FAT_CHAIN;
 525         info->type = type;
 526
 527         if (type == TYPE_FILE) {
 528                 info->attr = ATTR_ARCHIVE;
 529                 info->start_clu = EXFAT_EOF_CLUSTER;
 530                 info->size = 0;
 531                 info->num_subdirs = 0;
 532         } else {
 533                 int count;
 534                 struct exfat_chain cdir;
 535
 536                 info->attr = ATTR_SUBDIR;
 537                 info->start_clu = start_clu;
 538                 info->size = clu_size;
 539
 540                 exfat_chain_set(&cdir, info->start_clu,
 541                         EXFAT_B_TO_CLU(info->size, sbi), info->flags);
 542                 count = exfat_count_dir_entries(sb, &cdir);
 543                 if (count < 0)
 544                         return -EIO;
 545                 info->num_subdirs = count + EXFAT_MIN_SUBDIR;
 546         }
 547         memset(&info->crtime, 0, sizeof(info->crtime));
 548         memset(&info->mtime, 0, sizeof(info->mtime));
 549         memset(&info->atime, 0, sizeof(info->atime));
 550 out:
 551         return ret;
 552 }
 553
 554 static int exfat_create(struct inode *dir, struct dentry *dentry, umode_t mode,
 555                 bool excl)
 556 {
 557         struct super_block *sb = dir->i_sb;
 558         struct inode *inode;
 559         struct exfat_chain cdir;
 560         struct exfat_dir_entry info;
 561         loff_t i_pos;
 562         int err;
 563
 564         mutex_lock(&EXFAT_SB(sb)->s_lock);
 565         exfat_set_volume_dirty(sb);
 566         err = exfat_add_entry(dir, dentry->d_name.name, &cdir, TYPE_FILE,
 567                 &info);
 568         exfat_clear_volume_dirty(sb);
 569         if (err)
 570                 goto unlock;
 571
 572         inode_inc_iversion(dir);
 573         dir->i_ctime = dir->i_mtime = current_time(dir);
 574         if (IS_DIRSYNC(dir))
 575                 exfat_sync_inode(dir);
 576         else
 577                 mark_inode_dirty(dir);
 578
 579         i_pos = exfat_make_i_pos(&info);
 580         inode = exfat_build_inode(sb, &info, i_pos);
 581         err = PTR_ERR_OR_ZERO(inode);
 582         if (err)
 583                 goto unlock;
 584
 585         inode_inc_iversion(inode);
 586         inode->i_mtime = inode->i_atime = inode->i_ctime =
 587                 EXFAT_I(inode)->i_crtime = current_time(inode);
 588         exfat_truncate_atime(&inode->i_atime);
 589         /* timestamp is already written, so mark_inode_dirty() is unneeded. */
 590
 591         d_instantiate(dentry, inode);
 592 unlock:
 593         mutex_unlock(&EXFAT_SB(sb)->s_lock);
 594         return err;
 595 }
 596
 597 /* lookup a file */
 598 static int exfat_find(struct inode *dir, struct qstr *qname,
 599                 struct exfat_dir_entry *info)
 600 {
 601         int ret, dentry, num_entries, count;
 602         struct exfat_chain cdir;
 603         struct exfat_uni_name uni_name;
 604         struct super_block *sb = dir->i_sb;
 605         struct exfat_sb_info *sbi = EXFAT_SB(sb);
 606         struct exfat_inode_info *ei = EXFAT_I(dir);
 607
 608         if (qname->len == 0)
 609                 return -ENOENT;
 610
 611         /* check the validity of directory name in the given pathname */
 612         ret = exfat_resolve_path_for_lookup(dir, qname->name, &cdir, &uni_name);
 613         if (ret)
 614                 return ret;
 615
 616         num_entries = exfat_calc_num_entries(&uni_name);
 617         if (num_entries < 0)
 618                 return num_entries;
 619
 620         /* check the validation of hint_stat and initialize it if required */
 621         if (ei->version != (inode_peek_iversion_raw(dir) & 0xffffffff)) {
 622                 ei->hint_stat.clu = cdir.dir;
 623                 ei->hint_stat.eidx = 0;
 624                 ei->version = (inode_peek_iversion_raw(dir) & 0xffffffff);
 625                 ei->hint_femp.eidx = EXFAT_HINT_NONE;
 626         }
 627
 628         /* search the file name for directories */
 629         dentry = exfat_find_dir_entry(sb, ei, &cdir, &uni_name,
 630                         num_entries, TYPE_ALL);
 631
 632         if ((dentry < 0) && (dentry != -EEXIST))
 633                 return dentry; /* -error value */
 634
 635         memcpy(&info->dir, &cdir.dir, sizeof(struct exfat_chain));
 636         info->entry = dentry;
 637         info->num_subdirs = 0;
 638
 639         /* root directory itself */
 640         if (unlikely(dentry == -EEXIST)) {
 641                 int num_clu = 0;
 642
 643                 info->type = TYPE_DIR;
 644                 info->attr = ATTR_SUBDIR;
 645                 info->flags = ALLOC_FAT_CHAIN;
 646                 info->start_clu = sbi->root_dir;
 647                 memset(&info->crtime, 0, sizeof(info->crtime));
 648                 memset(&info->mtime, 0, sizeof(info->mtime));
 649                 memset(&info->atime, 0, sizeof(info->atime));
 650
 651                 exfat_chain_set(&cdir, sbi->root_dir, 0, ALLOC_FAT_CHAIN);
 652                 if (exfat_count_num_clusters(sb, &cdir, &num_clu))
 653                         return -EIO;
 654                 info->size = num_clu << sbi->cluster_size_bits;
 655
 656                 count = exfat_count_dir_entries(sb, &cdir);
 657                 if (count < 0)
 658                         return -EIO;
 659
 660                 info->num_subdirs = count;
 661         } else {
 662                 struct exfat_dentry *ep, *ep2;
 663                 struct exfat_entry_set_cache *es;
 664
 665                 es = exfat_get_dentry_set(sb, &cdir, dentry, ES_2_ENTRIES);
 666                 if (!es)
 667                         return -EIO;
 668                 ep = exfat_get_dentry_cached(es, 0);
 669                 ep2 = exfat_get_dentry_cached(es, 1);
 670
 671                 info->type = exfat_get_entry_type(ep);
 672                 info->attr = le16_to_cpu(ep->dentry.file.attr);
 673                 info->size = le64_to_cpu(ep2->dentry.stream.valid_size);
 674                 if ((info->type == TYPE_FILE) && (info->size == 0)) {
 675                         info->flags = ALLOC_NO_FAT_CHAIN;
 676                         info->start_clu = EXFAT_EOF_CLUSTER;
 677                 } else {
 678                         info->flags = ep2->dentry.stream.flags;
 679                         info->start_clu =
 680                                 le32_to_cpu(ep2->dentry.stream.start_clu);
 681                 }
 682
 683                 if (ei->start_clu == EXFAT_FREE_CLUSTER) {
 684                         exfat_fs_error(sb,
 685                                 "non-zero size file starts with zero cluster (size : %llu, p_dir : %u, entry : 0x%08x)",
 686                                 i_size_read(dir), ei->dir.dir, ei->entry);
 687                         exfat_free_dentry_set(es, false);
 688                         return -EIO;
 689                 }
 690
 691                 exfat_get_entry_time(sbi, &info->crtime,
 692                                 ep->dentry.file.create_tz,
 693                                 ep->dentry.file.create_time,
 694                                 ep->dentry.file.create_date,
 695                                 ep->dentry.file.create_time_cs);
 696                 exfat_get_entry_time(sbi, &info->mtime,
 697                                 ep->dentry.file.modify_tz,
 698                                 ep->dentry.file.modify_time,
 699                                 ep->dentry.file.modify_date,
 700                                 ep->dentry.file.modify_time_cs);
 701                 exfat_get_entry_time(sbi, &info->atime,
 702                                 ep->dentry.file.access_tz,
 703                                 ep->dentry.file.access_time,
 704                                 ep->dentry.file.access_date,
 705                                 0);
 706                 exfat_free_dentry_set(es, false);
 707
 708                 if (info->type == TYPE_DIR) {
 709                         exfat_chain_set(&cdir, info->start_clu,
 710                                 EXFAT_B_TO_CLU(info->size, sbi), info->flags);
 711                         count = exfat_count_dir_entries(sb, &cdir);
 712                         if (count < 0)
 713                                 return -EIO;
 714
 715                         info->num_subdirs = count + EXFAT_MIN_SUBDIR;
 716                 }
 717         }
 718         return 0;
 719 }
 720
 721 static int exfat_d_anon_disconn(struct dentry *dentry)
 722 {
 723         return IS_ROOT(dentry) && (dentry->d_flags & DCACHE_DISCONNECTED);
 724 }
 725
 726 static struct dentry *exfat_lookup(struct inode *dir, struct dentry *dentry,
 727                 unsigned int flags)
 728 {
 729         struct super_block *sb = dir->i_sb;
 730         struct inode *inode;
 731         struct dentry *alias;
 732         struct exfat_dir_entry info;
 733         int err;
 734         loff_t i_pos;
 735         mode_t i_mode;
 736
 737         mutex_lock(&EXFAT_SB(sb)->s_lock);
 738         err = exfat_find(dir, &dentry->d_name, &info);
 739         if (err) {
 740                 if (err == -ENOENT) {
 741                         inode = NULL;
 742                         goto out;
 743                 }
 744                 goto unlock;
 745         }
 746
 747         i_pos = exfat_make_i_pos(&info);
 748         inode = exfat_build_inode(sb, &info, i_pos);
 749         err = PTR_ERR_OR_ZERO(inode);
 750         if (err)
 751                 goto unlock;
 752
 753         i_mode = inode->i_mode;
 754         alias = d_find_alias(inode);
 755
 756         /*
 757          * Checking "alias->d_parent == dentry->d_parent" to make sure
 758          * FS is not corrupted (especially double linked dir).
 759          */
 760         if (alias && alias->d_parent == dentry->d_parent &&
 761                         !exfat_d_anon_disconn(alias)) {
 762
 763                 /*
 764                  * Unhashed alias is able to exist because of revalidate()
 765                  * called by lookup_fast. You can easily make this status
 766                  * by calling create and lookup concurrently
 767                  * In such case, we reuse an alias instead of new dentry
 768                  */
 769                 if (d_unhashed(alias)) {
 770                         WARN_ON(alias->d_name.hash_len !=
 771                                 dentry->d_name.hash_len);
 772                         exfat_info(sb, "rehashed a dentry(%p) in read lookup",
 773                                    alias);
 774                         d_drop(dentry);
 775                         d_rehash(alias);
 776                 } else if (!S_ISDIR(i_mode)) {
 777                         /*
 778                          * This inode has non anonymous-DCACHE_DISCONNECTED
 779                          * dentry. This means, the user did ->lookup() by an
 780                          * another name (longname vs 8.3 alias of it) in past.
 781                          *
 782                          * Switch to new one for reason of locality if possible.
 783                          */
 784                         d_move(alias, dentry);
 785                 }
 786                 iput(inode);
 787                 mutex_unlock(&EXFAT_SB(sb)->s_lock);
 788                 return alias;
 789         }
 790         dput(alias);
 791 out:
 792         mutex_unlock(&EXFAT_SB(sb)->s_lock);
 793         if (!inode)
 794                 exfat_d_version_set(dentry, inode_query_iversion(dir));
 795
 796         return d_splice_alias(inode, dentry);
 797 unlock:
 798         mutex_unlock(&EXFAT_SB(sb)->s_lock);
 799         return ERR_PTR(err);
 800 }
 801
 802 /* remove an entry, BUT don't truncate */
 803 static int exfat_unlink(struct inode *dir, struct dentry *dentry)
 804 {
 805         struct exfat_chain cdir;
 806         struct exfat_dentry *ep;
 807         struct super_block *sb = dir->i_sb;
 808         struct inode *inode = dentry->d_inode;
 809         struct exfat_inode_info *ei = EXFAT_I(inode);
 810         struct buffer_head *bh;
 811         sector_t sector;
 812         int num_entries, entry, err = 0;
 813
 814         mutex_lock(&EXFAT_SB(sb)->s_lock);
 815         exfat_chain_dup(&cdir, &ei->dir);
 816         entry = ei->entry;
 817         if (ei->dir.dir == DIR_DELETED) {
 818                 exfat_err(sb, "abnormal access to deleted dentry");
 819                 err = -ENOENT;
 820                 goto unlock;
 821         }
 822
 823         ep = exfat_get_dentry(sb, &cdir, entry, &bh, &sector);
 824         if (!ep) {
 825                 err = -EIO;
 826                 goto unlock;
 827         }
 828         num_entries = exfat_count_ext_entries(sb, &cdir, entry, ep);
 829         if (num_entries < 0) {
 830                 err = -EIO;
 831                 brelse(bh);
 832                 goto unlock;
 833         }
 834         num_entries++;
 835         brelse(bh);
 836
 837         exfat_set_volume_dirty(sb);
 838         /* update the directory entry */
 839         if (exfat_remove_entries(dir, &cdir, entry, 0, num_entries)) {
 840                 err = -EIO;
 841                 goto unlock;
 842         }
 843
 844         /* This doesn't modify ei */
 845         ei->dir.dir = DIR_DELETED;
 846         exfat_clear_volume_dirty(sb);
 847
 848         inode_inc_iversion(dir);
 849         dir->i_mtime = dir->i_atime = current_time(dir);
 850         exfat_truncate_atime(&dir->i_atime);
 851         if (IS_DIRSYNC(dir))
 852                 exfat_sync_inode(dir);
 853         else
 854                 mark_inode_dirty(dir);
 855
 856         clear_nlink(inode);
 857         inode->i_mtime = inode->i_atime = current_time(inode);
 858         exfat_truncate_atime(&inode->i_atime);
 859         exfat_unhash_inode(inode);
 860         exfat_d_version_set(dentry, inode_query_iversion(dir));
 861 unlock:
 862         mutex_unlock(&EXFAT_SB(sb)->s_lock);
 863         return err;
 864 }
 865
 866 static int exfat_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
 867 {
 868         struct super_block *sb = dir->i_sb;
 869         struct inode *inode;
 870         struct exfat_dir_entry info;
 871         struct exfat_chain cdir;
 872         loff_t i_pos;
 873         int err;
 874
 875         mutex_lock(&EXFAT_SB(sb)->s_lock);
 876         exfat_set_volume_dirty(sb);
 877         err = exfat_add_entry(dir, dentry->d_name.name, &cdir, TYPE_DIR,
 878                 &info);
 879         exfat_clear_volume_dirty(sb);
 880         if (err)
 881                 goto unlock;
 882
 883         inode_inc_iversion(dir);
 884         dir->i_ctime = dir->i_mtime = current_time(dir);
 885         if (IS_DIRSYNC(dir))
 886                 exfat_sync_inode(dir);
 887         else
 888                 mark_inode_dirty(dir);
 889         inc_nlink(dir);
 890
 891         i_pos = exfat_make_i_pos(&info);
 892         inode = exfat_build_inode(sb, &info, i_pos);
 893         err = PTR_ERR_OR_ZERO(inode);
 894         if (err)
 895                 goto unlock;
 896
 897         inode_inc_iversion(inode);
 898         inode->i_mtime = inode->i_atime = inode->i_ctime =
 899                 EXFAT_I(inode)->i_crtime = current_time(inode);
 900         exfat_truncate_atime(&inode->i_atime);
 901         /* timestamp is already written, so mark_inode_dirty() is unneeded. */
 902
 903         d_instantiate(dentry, inode);
 904
 905 unlock:
 906         mutex_unlock(&EXFAT_SB(sb)->s_lock);
 907         return err;
 908 }
 909
 910 static int exfat_check_dir_empty(struct super_block *sb,
 911                 struct exfat_chain *p_dir)
 912 {
 913         int i, dentries_per_clu;
 914         unsigned int type;
 915         struct exfat_chain clu;
 916         struct exfat_dentry *ep;
 917         struct exfat_sb_info *sbi = EXFAT_SB(sb);
 918         struct buffer_head *bh;
 919
 920         dentries_per_clu = sbi->dentries_per_clu;
 921
 922         exfat_chain_dup(&clu, p_dir);
 923
 924         while (clu.dir != EXFAT_EOF_CLUSTER) {
 925                 for (i = 0; i < dentries_per_clu; i++) {
 926                         ep = exfat_get_dentry(sb, &clu, i, &bh, NULL);
 927                         if (!ep)
 928                                 return -EIO;
 929                         type = exfat_get_entry_type(ep);
 930                         brelse(bh);
 931                         if (type == TYPE_UNUSED)
 932                                 return 0;
 933
 934                         if (type != TYPE_FILE && type != TYPE_DIR)
 935                                 continue;
 936
 937                         return -ENOTEMPTY;
 938                 }
 939
 940                 if (clu.flags == ALLOC_NO_FAT_CHAIN) {
 941                         if (--clu.size > 0)
 942                                 clu.dir++;
 943                         else
 944                                 clu.dir = EXFAT_EOF_CLUSTER;
 945                 } else {
 946                         if (exfat_get_next_cluster(sb, &(clu.dir)))
 947                                 return -EIO;
 948                 }
 949         }
 950
 951         return 0;
 952 }
 953
 954 static int exfat_rmdir(struct inode *dir, struct dentry *dentry)
 955 {
 956         struct inode *inode = dentry->d_inode;
 957         struct exfat_dentry *ep;
 958         struct exfat_chain cdir, clu_to_free;
 959         struct super_block *sb = inode->i_sb;
 960         struct exfat_sb_info *sbi = EXFAT_SB(sb);
 961         struct exfat_inode_info *ei = EXFAT_I(inode);
 962         struct buffer_head *bh;
 963         sector_t sector;
 964         int num_entries, entry, err;
 965
 966         mutex_lock(&EXFAT_SB(inode->i_sb)->s_lock);
 967
 968         exfat_chain_dup(&cdir, &ei->dir);
 969         entry = ei->entry;
 970
 971         if (ei->dir.dir == DIR_DELETED) {
 972                 exfat_err(sb, "abnormal access to deleted dentry");
 973                 err = -ENOENT;
 974                 goto unlock;
 975         }
 976
 977         exfat_chain_set(&clu_to_free, ei->start_clu,
 978                 EXFAT_B_TO_CLU_ROUND_UP(i_size_read(inode), sbi), ei->flags);
 979
 980         err = exfat_check_dir_empty(sb, &clu_to_free);
 981         if (err) {
 982                 if (err == -EIO)
 983                         exfat_err(sb, "failed to exfat_check_dir_empty : err(%d)",
 984                                   err);
 985                 goto unlock;
 986         }
 987
 988         ep = exfat_get_dentry(sb, &cdir, entry, &bh, &sector);
 989         if (!ep) {
 990                 err = -EIO;
 991                 goto unlock;
 992         }
 993
 994         num_entries = exfat_count_ext_entries(sb, &cdir, entry, ep);
 995         if (num_entries < 0) {
 996                 err = -EIO;
 997                 brelse(bh);
 998                 goto unlock;
 999         }
1000         num_entries++;
1001         brelse(bh);
1002
1003         exfat_set_volume_dirty(sb);
1004         err = exfat_remove_entries(dir, &cdir, entry, 0, num_entries);
1005         if (err) {
1006                 exfat_err(sb, "failed to exfat_remove_entries : err(%d)", err);
1007                 goto unlock;
1008         }
1009         ei->dir.dir = DIR_DELETED;
1010         exfat_clear_volume_dirty(sb);
1011
1012         inode_inc_iversion(dir);
1013         dir->i_mtime = dir->i_atime = current_time(dir);
1014         exfat_truncate_atime(&dir->i_atime);
1015         if (IS_DIRSYNC(dir))
1016                 exfat_sync_inode(dir);
1017         else
1018                 mark_inode_dirty(dir);
1019         drop_nlink(dir);
1020
1021         clear_nlink(inode);
1022         inode->i_mtime = inode->i_atime = current_time(inode);
1023         exfat_truncate_atime(&inode->i_atime);
1024         exfat_unhash_inode(inode);
1025         exfat_d_version_set(dentry, inode_query_iversion(dir));
1026 unlock:
1027         mutex_unlock(&EXFAT_SB(inode->i_sb)->s_lock);
1028         return err;
1029 }
1030
1031 static int exfat_rename_file(struct inode *inode, struct exfat_chain *p_dir,
1032                 int oldentry, struct exfat_uni_name *p_uniname,
1033                 struct exfat_inode_info *ei)
1034 {
1035         int ret, num_old_entries, num_new_entries;
1036         sector_t sector_old, sector_new;
1037         struct exfat_dentry *epold, *epnew;
1038         struct super_block *sb = inode->i_sb;
1039         struct buffer_head *new_bh, *old_bh;
1040         int sync = IS_DIRSYNC(inode);
1041
1042         epold = exfat_get_dentry(sb, p_dir, oldentry, &old_bh, &sector_old);
1043         if (!epold)
1044                 return -EIO;
1045
1046         num_old_entries = exfat_count_ext_entries(sb, p_dir, oldentry, epold);
1047         if (num_old_entries < 0)
1048                 return -EIO;
1049         num_old_entries++;
1050
1051         num_new_entries = exfat_calc_num_entries(p_uniname);
1052         if (num_new_entries < 0)
1053                 return num_new_entries;
1054
1055         if (num_old_entries < num_new_entries) {
1056                 int newentry;
1057
1058                 newentry =
1059                         exfat_find_empty_entry(inode, p_dir, num_new_entries);
1060                 if (newentry < 0)
1061                         return newentry; /* -EIO or -ENOSPC */
1062
1063                 epnew = exfat_get_dentry(sb, p_dir, newentry, &new_bh,
1064                         &sector_new);
1065                 if (!epnew)
1066                         return -EIO;
1067
1068                 memcpy(epnew, epold, DENTRY_SIZE);
1069                 if (exfat_get_entry_type(epnew) == TYPE_FILE) {
1070                         epnew->dentry.file.attr |= cpu_to_le16(ATTR_ARCHIVE);
1071                         ei->attr |= ATTR_ARCHIVE;
1072                 }
1073                 exfat_update_bh(new_bh, sync);
1074                 brelse(old_bh);
1075                 brelse(new_bh);
1076
1077                 epold = exfat_get_dentry(sb, p_dir, oldentry + 1, &old_bh,
1078                         &sector_old);
1079                 if (!epold)
1080                         return -EIO;
1081                 epnew = exfat_get_dentry(sb, p_dir, newentry + 1, &new_bh,
1082                         &sector_new);
1083                 if (!epnew) {
1084                         brelse(old_bh);
1085                         return -EIO;
1086                 }
1087
1088                 memcpy(epnew, epold, DENTRY_SIZE);
1089                 exfat_update_bh(new_bh, sync);
1090                 brelse(old_bh);
1091                 brelse(new_bh);
1092
1093                 ret = exfat_init_ext_entry(inode, p_dir, newentry,
1094                         num_new_entries, p_uniname);
1095                 if (ret)
1096                         return ret;
1097
1098                 exfat_remove_entries(inode, p_dir, oldentry, 0,
1099                         num_old_entries);
1100                 ei->entry = newentry;
1101         } else {
1102                 if (exfat_get_entry_type(epold) == TYPE_FILE) {
1103                         epold->dentry.file.attr |= cpu_to_le16(ATTR_ARCHIVE);
1104                         ei->attr |= ATTR_ARCHIVE;
1105                 }
1106                 exfat_update_bh(old_bh, sync);
1107                 brelse(old_bh);
1108                 ret = exfat_init_ext_entry(inode, p_dir, oldentry,
1109                         num_new_entries, p_uniname);
1110                 if (ret)
1111                         return ret;
1112
1113                 exfat_remove_entries(inode, p_dir, oldentry, num_new_entries,
1114                         num_old_entries);
1115         }
1116         return 0;
1117 }
1118
1119 static int exfat_move_file(struct inode *inode, struct exfat_chain *p_olddir,
1120                 int oldentry, struct exfat_chain *p_newdir,
1121                 struct exfat_uni_name *p_uniname, struct exfat_inode_info *ei)
1122 {
1123         int ret, newentry, num_new_entries, num_old_entries;
1124         sector_t sector_mov, sector_new;
1125         struct exfat_dentry *epmov, *epnew;
1126         struct super_block *sb = inode->i_sb;
1127         struct buffer_head *mov_bh, *new_bh;
1128
1129         epmov = exfat_get_dentry(sb, p_olddir, oldentry, &mov_bh, &sector_mov);
1130         if (!epmov)
1131                 return -EIO;
1132
1133         /* check if the source and target directory is the same */
1134         if (exfat_get_entry_type(epmov) == TYPE_DIR &&
1135             le32_to_cpu(epmov->dentry.stream.start_clu) == p_newdir->dir)
1136                 return -EINVAL;
1137
1138         num_old_entries = exfat_count_ext_entries(sb, p_olddir, oldentry,
1139                 epmov);
1140         if (num_old_entries < 0)
1141                 return -EIO;
1142         num_old_entries++;
1143
1144         num_new_entries = exfat_calc_num_entries(p_uniname);
1145         if (num_new_entries < 0)
1146                 return num_new_entries;
1147
1148         newentry = exfat_find_empty_entry(inode, p_newdir, num_new_entries);
1149         if (newentry < 0)
1150                 return newentry; /* -EIO or -ENOSPC */
1151
1152         epnew = exfat_get_dentry(sb, p_newdir, newentry, &new_bh, &sector_new);
1153         if (!epnew)
1154                 return -EIO;
1155
1156         memcpy(epnew, epmov, DENTRY_SIZE);
1157         if (exfat_get_entry_type(epnew) == TYPE_FILE) {
1158                 epnew->dentry.file.attr |= cpu_to_le16(ATTR_ARCHIVE);
1159                 ei->attr |= ATTR_ARCHIVE;
1160         }
1161         exfat_update_bh(new_bh, IS_DIRSYNC(inode));
1162         brelse(mov_bh);
1163         brelse(new_bh);
1164
1165         epmov = exfat_get_dentry(sb, p_olddir, oldentry + 1, &mov_bh,
1166                 &sector_mov);
1167         if (!epmov)
1168                 return -EIO;
1169         epnew = exfat_get_dentry(sb, p_newdir, newentry + 1, &new_bh,
1170                 &sector_new);
1171         if (!epnew) {
1172                 brelse(mov_bh);
1173                 return -EIO;
1174         }
1175
1176         memcpy(epnew, epmov, DENTRY_SIZE);
1177         exfat_update_bh(new_bh, IS_DIRSYNC(inode));
1178         brelse(mov_bh);
1179         brelse(new_bh);
1180
1181         ret = exfat_init_ext_entry(inode, p_newdir, newentry, num_new_entries,
1182                 p_uniname);
1183         if (ret)
1184                 return ret;
1185
1186         exfat_remove_entries(inode, p_olddir, oldentry, 0, num_old_entries);
1187
1188         exfat_chain_set(&ei->dir, p_newdir->dir, p_newdir->size,
1189                 p_newdir->flags);
1190
1191         ei->entry = newentry;
1192         return 0;
1193 }
1194
1195 static void exfat_update_parent_info(struct exfat_inode_info *ei,
1196                 struct inode *parent_inode)
1197 {
1198         struct exfat_sb_info *sbi = EXFAT_SB(parent_inode->i_sb);
1199         struct exfat_inode_info *parent_ei = EXFAT_I(parent_inode);
1200         loff_t parent_isize = i_size_read(parent_inode);
1201
1202         /*
1203          * the problem that struct exfat_inode_info caches wrong parent info.
1204          *
1205          * because of flag-mismatch of ei->dir,
1206          * there is abnormal traversing cluster chain.
1207          */
1208         if (unlikely(parent_ei->flags != ei->dir.flags ||
1209                      parent_isize != EXFAT_CLU_TO_B(ei->dir.size, sbi) ||
1210                      parent_ei->start_clu != ei->dir.dir)) {
1211                 exfat_chain_set(&ei->dir, parent_ei->start_clu,
1212                         EXFAT_B_TO_CLU_ROUND_UP(parent_isize, sbi),
1213                         parent_ei->flags);
1214         }
1215 }
1216
1217 /* rename or move a old file into a new file */
1218 static int __exfat_rename(struct inode *old_parent_inode,
1219                 struct exfat_inode_info *ei, struct inode *new_parent_inode,
1220                 struct dentry *new_dentry)
1221 {
1222         int ret;
1223         int dentry;
1224         struct exfat_chain olddir, newdir;
1225         struct exfat_chain *p_dir = NULL;
1226         struct exfat_uni_name uni_name;
1227         struct exfat_dentry *ep;
1228         struct super_block *sb = old_parent_inode->i_sb;
1229         struct exfat_sb_info *sbi = EXFAT_SB(sb);
1230         const unsigned char *new_path = new_dentry->d_name.name;
1231         struct inode *new_inode = new_dentry->d_inode;
1232         int num_entries;
1233         struct exfat_inode_info *new_ei = NULL;
1234         unsigned int new_entry_type = TYPE_UNUSED;
1235         int new_entry = 0;
1236         struct buffer_head *old_bh, *new_bh = NULL;
1237
1238         /* check the validity of pointer parameters */
1239         if (new_path == NULL || strlen(new_path) == 0)
1240                 return -EINVAL;
1241
1242         if (ei->dir.dir == DIR_DELETED) {
1243                 exfat_err(sb, "abnormal access to deleted source dentry");
1244                 return -ENOENT;
1245         }
1246
1247         exfat_update_parent_info(ei, old_parent_inode);
1248
1249         exfat_chain_dup(&olddir, &ei->dir);
1250         dentry = ei->entry;
1251
1252         ep = exfat_get_dentry(sb, &olddir, dentry, &old_bh, NULL);
1253         if (!ep) {
1254                 ret = -EIO;
1255                 goto out;
1256         }
1257         brelse(old_bh);
1258
1259         /* check whether new dir is existing directory and empty */
1260         if (new_inode) {
1261                 ret = -EIO;
1262                 new_ei = EXFAT_I(new_inode);
1263
1264                 if (new_ei->dir.dir == DIR_DELETED) {
1265                         exfat_err(sb, "abnormal access to deleted target dentry");
1266                         goto out;
1267                 }
1268
1269                 exfat_update_parent_info(new_ei, new_parent_inode);
1270
1271                 p_dir = &(new_ei->dir);
1272                 new_entry = new_ei->entry;
1273                 ep = exfat_get_dentry(sb, p_dir, new_entry, &new_bh, NULL);
1274                 if (!ep)
1275                         goto out;
1276
1277                 new_entry_type = exfat_get_entry_type(ep);
1278                 brelse(new_bh);
1279
1280                 /* if new_inode exists, update ei */
1281                 if (new_entry_type == TYPE_DIR) {
1282                         struct exfat_chain new_clu;
1283
1284                         new_clu.dir = new_ei->start_clu;
1285                         new_clu.size =
1286                                 EXFAT_B_TO_CLU_ROUND_UP(i_size_read(new_inode),
1287                                 sbi);
1288                         new_clu.flags = new_ei->flags;
1289
1290                         ret = exfat_check_dir_empty(sb, &new_clu);
1291                         if (ret)
1292                                 goto out;
1293                 }
1294         }
1295
1296         /* check the validity of directory name in the given new pathname */
1297         ret = exfat_resolve_path(new_parent_inode, new_path, &newdir,
1298                         &uni_name);
1299         if (ret)
1300                 goto out;
1301
1302         exfat_set_volume_dirty(sb);
1303
1304         if (olddir.dir == newdir.dir)
1305                 ret = exfat_rename_file(new_parent_inode, &olddir, dentry,
1306                                 &uni_name, ei);
1307         else
1308                 ret = exfat_move_file(new_parent_inode, &olddir, dentry,
1309                                 &newdir, &uni_name, ei);
1310
1311         if (!ret && new_inode) {
1312                 /* delete entries of new_dir */
1313                 ep = exfat_get_dentry(sb, p_dir, new_entry, &new_bh, NULL);
1314                 if (!ep) {
1315                         ret = -EIO;
1316                         goto del_out;
1317                 }
1318
1319                 num_entries = exfat_count_ext_entries(sb, p_dir, new_entry, ep);
1320                 if (num_entries < 0) {
1321                         ret = -EIO;
1322                         goto del_out;
1323                 }
1324                 brelse(new_bh);
1325
1326                 if (exfat_remove_entries(new_inode, p_dir, new_entry, 0,
1327                                 num_entries + 1)) {
1328                         ret = -EIO;
1329                         goto del_out;
1330                 }
1331
1332                 /* Free the clusters if new_inode is a dir(as if exfat_rmdir) */
1333                 if (new_entry_type == TYPE_DIR) {
1334                         /* new_ei, new_clu_to_free */
1335                         struct exfat_chain new_clu_to_free;
1336
1337                         exfat_chain_set(&new_clu_to_free, new_ei->start_clu,
1338                                 EXFAT_B_TO_CLU_ROUND_UP(i_size_read(new_inode),
1339                                 sbi), new_ei->flags);
1340
1341                         if (exfat_free_cluster(new_inode, &new_clu_to_free)) {
1342                                 /* just set I/O error only */
1343                                 ret = -EIO;
1344                         }
1345
1346                         i_size_write(new_inode, 0);
1347                         new_ei->start_clu = EXFAT_EOF_CLUSTER;
1348                         new_ei->flags = ALLOC_NO_FAT_CHAIN;
1349                 }
1350 del_out:
1351                 /* Update new_inode ei
1352                  * Prevent syncing removed new_inode
1353                  * (new_ei is already initialized above code ("if (new_inode)")
1354                  */
1355                 new_ei->dir.dir = DIR_DELETED;
1356         }
1357         exfat_clear_volume_dirty(sb);
1358 out:
1359         return ret;
1360 }
1361
1362 static int exfat_rename(struct inode *old_dir, struct dentry *old_dentry,
1363                 struct inode *new_dir, struct dentry *new_dentry,
1364                 unsigned int flags)
1365 {
1366         struct inode *old_inode, *new_inode;
1367         struct super_block *sb = old_dir->i_sb;
1368         loff_t i_pos;
1369         int err;
1370
1371         /*
1372          * The VFS already checks for existence, so for local filesystems
1373          * the RENAME_NOREPLACE implementation is equivalent to plain rename.
1374          * Don't support any other flags
1375          */
1376         if (flags & ~RENAME_NOREPLACE)
1377                 return -EINVAL;
1378
1379         mutex_lock(&EXFAT_SB(sb)->s_lock);
1380         old_inode = old_dentry->d_inode;
1381         new_inode = new_dentry->d_inode;
1382
1383         err = __exfat_rename(old_dir, EXFAT_I(old_inode), new_dir, new_dentry);
1384         if (err)
1385                 goto unlock;
1386
1387         inode_inc_iversion(new_dir);
1388         new_dir->i_ctime = new_dir->i_mtime = new_dir->i_atime =
1389                 EXFAT_I(new_dir)->i_crtime = current_time(new_dir);
1390         exfat_truncate_atime(&new_dir->i_atime);
1391         if (IS_DIRSYNC(new_dir))
1392                 exfat_sync_inode(new_dir);
1393         else
1394                 mark_inode_dirty(new_dir);
1395
1396         i_pos = ((loff_t)EXFAT_I(old_inode)->dir.dir << 32) |
1397                 (EXFAT_I(old_inode)->entry & 0xffffffff);
1398         exfat_unhash_inode(old_inode);
1399         exfat_hash_inode(old_inode, i_pos);
1400         if (IS_DIRSYNC(new_dir))
1401                 exfat_sync_inode(old_inode);
1402         else
1403                 mark_inode_dirty(old_inode);
1404
1405         if (S_ISDIR(old_inode->i_mode) && old_dir != new_dir) {
1406                 drop_nlink(old_dir);
1407                 if (!new_inode)
1408                         inc_nlink(new_dir);
1409         }
1410
1411         inode_inc_iversion(old_dir);
1412         old_dir->i_ctime = old_dir->i_mtime = current_time(old_dir);
1413         if (IS_DIRSYNC(old_dir))
1414                 exfat_sync_inode(old_dir);
1415         else
1416                 mark_inode_dirty(old_dir);
1417
1418         if (new_inode) {
1419                 exfat_unhash_inode(new_inode);
1420
1421                 /* skip drop_nlink if new_inode already has been dropped */
1422                 if (new_inode->i_nlink) {
1423                         drop_nlink(new_inode);
1424                         if (S_ISDIR(new_inode->i_mode))
1425                                 drop_nlink(new_inode);
1426                 } else {
1427                         exfat_warn(sb, "abnormal access to an inode dropped");
1428                         WARN_ON(new_inode->i_nlink == 0);
1429                 }
1430                 new_inode->i_ctime = EXFAT_I(new_inode)->i_crtime =
1431                         current_time(new_inode);
1432         }
1433
1434 unlock:
1435         mutex_unlock(&EXFAT_SB(sb)->s_lock);
1436         return err;
1437 }
1438
1439 const struct inode_operations exfat_dir_inode_operations = {
1440         .create         = exfat_create,
1441         .lookup         = exfat_lookup,
1442         .unlink         = exfat_unlink,
1443         .mkdir          = exfat_mkdir,
1444         .rmdir          = exfat_rmdir,
1445         .rename         = exfat_rename,
1446         .setattr        = exfat_setattr,
1447         .getattr        = exfat_getattr,
1448 };