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