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 inode *dir, const struct qstr *name,
  35                               struct dentry *dentry, unsigned int flags)
  36 {
  37         if (flags & LOOKUP_RCU)
  38                 return -ECHILD;
  39
  40         /*
  41          * This is not negative dentry. Always valid.
  42          *
  43          * Note, rename() to existing directory entry will have ->d_inode, and
  44          * will use existing name which isn't specified name by user.
  45          *
  46          * We may be able to drop this positive dentry here. But dropping
  47          * positive dentry isn't good idea. So it's unsupported like
  48          * rename("filename", "FILENAME") for now.
  49          */
  50         if (d_really_is_positive(dentry))
  51                 return 1;
  52
  53         /*
  54          * Drop the negative dentry, in order to make sure to use the case
  55          * sensitive name which is specified by user if this is for creation.
  56          */
  57         if (flags & (LOOKUP_CREATE | LOOKUP_RENAME_TARGET))
  58                 return 0;
  59
  60         return inode_eq_iversion(dir, exfat_d_version(dentry));
  61 }
  62
  63 /* returns the length of a struct qstr, ignoring trailing dots if necessary */
  64 static unsigned int exfat_striptail_len(unsigned int len, const char *name,
  65                                         bool keep_last_dots)
  66 {
  67         if (!keep_last_dots) {
  68                 while (len && name[len - 1] == '.')
  69                         len--;
  70         }
  71         return len;
  72 }
  73
  74 /*
  75  * Compute the hash for the exfat name corresponding to the dentry.  If the name
  76  * is invalid, we leave the hash code unchanged so that the existing dentry can
  77  * be used. The exfat fs routines will return ENOENT or EINVAL as appropriate.
  78  */
  79 static int exfat_d_hash(const struct dentry *dentry, struct qstr *qstr)
  80 {
  81         struct super_block *sb = dentry->d_sb;
  82         struct nls_table *t = EXFAT_SB(sb)->nls_io;
  83         const unsigned char *name = qstr->name;
  84         unsigned int len = exfat_striptail_len(qstr->len, qstr->name,
  85                            EXFAT_SB(sb)->options.keep_last_dots);
  86         unsigned long hash = init_name_hash(dentry);
  87         int i, charlen;
  88         wchar_t c;
  89
  90         for (i = 0; i < len; i += charlen) {
  91                 charlen = t->char2uni(&name[i], len - i, &c);
  92                 if (charlen < 0)
  93                         return charlen;
  94                 hash = partial_name_hash(exfat_toupper(sb, c), hash);
  95         }
  96
  97         qstr->hash = end_name_hash(hash);
  98         return 0;
  99 }
 100
 101 static int exfat_d_cmp(const struct dentry *dentry, unsigned int len,
 102                 const char *str, const struct qstr *name)
 103 {
 104         struct super_block *sb = dentry->d_sb;
 105         struct nls_table *t = EXFAT_SB(sb)->nls_io;
 106         unsigned int alen = exfat_striptail_len(name->len, name->name,
 107                                 EXFAT_SB(sb)->options.keep_last_dots);
 108         unsigned int blen = exfat_striptail_len(len, str,
 109                                 EXFAT_SB(sb)->options.keep_last_dots);
 110         wchar_t c1, c2;
 111         int charlen, i;
 112
 113         if (alen != blen)
 114                 return 1;
 115
 116         for (i = 0; i < len; i += charlen) {
 117                 charlen = t->char2uni(&name->name[i], alen - i, &c1);
 118                 if (charlen < 0)
 119                         return 1;
 120                 if (charlen != t->char2uni(&str[i], blen - i, &c2))
 121                         return 1;
 122
 123                 if (exfat_toupper(sb, c1) != exfat_toupper(sb, c2))
 124                         return 1;
 125         }
 126
 127         return 0;
 128 }
 129
 130 const struct dentry_operations exfat_dentry_ops = {
 131         .d_revalidate   = exfat_d_revalidate,
 132         .d_hash         = exfat_d_hash,
 133         .d_compare      = exfat_d_cmp,
 134 };
 135
 136 static int exfat_utf8_d_hash(const struct dentry *dentry, struct qstr *qstr)
 137 {
 138         struct super_block *sb = dentry->d_sb;
 139         const unsigned char *name = qstr->name;
 140         unsigned int len = exfat_striptail_len(qstr->len, qstr->name,
 141                                EXFAT_SB(sb)->options.keep_last_dots);
 142         unsigned long hash = init_name_hash(dentry);
 143         int i, charlen;
 144         unicode_t u;
 145
 146         for (i = 0; i < len; i += charlen) {
 147                 charlen = utf8_to_utf32(&name[i], len - i, &u);
 148                 if (charlen < 0)
 149                         return charlen;
 150
 151                 /*
 152                  * exfat_toupper() works only for code points up to the U+FFFF.
 153                  */
 154                 hash = partial_name_hash(u <= 0xFFFF ? exfat_toupper(sb, u) : u,
 155                                          hash);
 156         }
 157
 158         qstr->hash = end_name_hash(hash);
 159         return 0;
 160 }
 161
 162 static int exfat_utf8_d_cmp(const struct dentry *dentry, unsigned int len,
 163                 const char *str, const struct qstr *name)
 164 {
 165         struct super_block *sb = dentry->d_sb;
 166         unsigned int alen = exfat_striptail_len(name->len, name->name,
 167                                 EXFAT_SB(sb)->options.keep_last_dots);
 168         unsigned int blen = exfat_striptail_len(len, str,
 169                                 EXFAT_SB(sb)->options.keep_last_dots);
 170
 171         unicode_t u_a, u_b;
 172         int charlen, i;
 173
 174         if (alen != blen)
 175                 return 1;
 176
 177         for (i = 0; i < alen; i += charlen) {
 178                 charlen = utf8_to_utf32(&name->name[i], alen - i, &u_a);
 179                 if (charlen < 0)
 180                         return 1;
 181                 if (charlen != utf8_to_utf32(&str[i], blen - i, &u_b))
 182                         return 1;
 183
 184                 if (u_a <= 0xFFFF && u_b <= 0xFFFF) {
 185                         if (exfat_toupper(sb, u_a) != exfat_toupper(sb, u_b))
 186                                 return 1;
 187                 } else {
 188                         if (u_a != u_b)
 189                                 return 1;
 190                 }
 191         }
 192
 193         return 0;
 194 }
 195
 196 const struct dentry_operations exfat_utf8_dentry_ops = {
 197         .d_revalidate   = exfat_d_revalidate,
 198         .d_hash         = exfat_utf8_d_hash,
 199         .d_compare      = exfat_utf8_d_cmp,
 200 };
 201
 202 /* search EMPTY CONTINUOUS "num_entries" entries */
 203 static int exfat_search_empty_slot(struct super_block *sb,
 204                 struct exfat_hint_femp *hint_femp, struct exfat_chain *p_dir,
 205                 int num_entries, struct exfat_entry_set_cache *es)
 206 {
 207         int i, dentry, ret;
 208         int dentries_per_clu;
 209         struct exfat_chain clu;
 210         struct exfat_sb_info *sbi = EXFAT_SB(sb);
 211         int total_entries = EXFAT_CLU_TO_DEN(p_dir->size, sbi);
 212
 213         dentries_per_clu = sbi->dentries_per_clu;
 214
 215         if (hint_femp->eidx != EXFAT_HINT_NONE) {
 216                 dentry = hint_femp->eidx;
 217
 218                 /*
 219                  * If hint_femp->count is enough, it is needed to check if
 220                  * there are actual empty entries.
 221                  * Otherwise, and if "dentry + hint_famp->count" is also equal
 222                  * to "p_dir->size * dentries_per_clu", it means ENOSPC.
 223                  */
 224                 if (dentry + hint_femp->count == total_entries &&
 225                     num_entries > hint_femp->count)
 226                         return -ENOSPC;
 227
 228                 hint_femp->eidx = EXFAT_HINT_NONE;
 229                 exfat_chain_dup(&clu, &hint_femp->cur);
 230         } else {
 231                 exfat_chain_dup(&clu, p_dir);
 232                 dentry = 0;
 233         }
 234
 235         while (dentry + num_entries <= total_entries &&
 236                clu.dir != EXFAT_EOF_CLUSTER) {
 237                 i = dentry & (dentries_per_clu - 1);
 238
 239                 ret = exfat_get_empty_dentry_set(es, sb, &clu, i, num_entries);
 240                 if (ret < 0)
 241                         return ret;
 242                 else if (ret == 0)
 243                         return dentry;
 244
 245                 dentry += ret;
 246                 i += ret;
 247
 248                 while (i >= dentries_per_clu) {
 249                         if (clu.flags == ALLOC_NO_FAT_CHAIN) {
 250                                 if (--clu.size > 0)
 251                                         clu.dir++;
 252                                 else
 253                                         clu.dir = EXFAT_EOF_CLUSTER;
 254                         } else {
 255                                 if (exfat_get_next_cluster(sb, &clu.dir))
 256                                         return -EIO;
 257                         }
 258
 259                         i -= dentries_per_clu;
 260                 }
 261         }
 262
 263         hint_femp->eidx = dentry;
 264         hint_femp->count = 0;
 265         if (dentry == total_entries || clu.dir == EXFAT_EOF_CLUSTER)
 266                 exfat_chain_set(&hint_femp->cur, EXFAT_EOF_CLUSTER, 0,
 267                                 clu.flags);
 268         else
 269                 hint_femp->cur = clu;
 270
 271         return -ENOSPC;
 272 }
 273
 274 static int exfat_check_max_dentries(struct inode *inode)
 275 {
 276         if (EXFAT_B_TO_DEN(i_size_read(inode)) >= MAX_EXFAT_DENTRIES) {
 277                 /*
 278                  * exFAT spec allows a dir to grow up to 8388608(256MB)
 279                  * dentries
 280                  */
 281                 return -ENOSPC;
 282         }
 283         return 0;
 284 }
 285
 286 /*
 287  * Find an empty directory entry set.
 288  *
 289  * If there isn't any empty slot, expand cluster chain.
 290  *
 291  * in:
 292  *   inode: inode of the parent directory
 293  *   num_entries: specifies how many dentries in the empty directory entry set
 294  *
 295  * out:
 296  *   p_dir: the cluster where the empty directory entry set is located
 297  *   es: The found empty directory entry set
 298  *
 299  * return:
 300  *   the directory entry index in p_dir is returned on succeeds
 301  *   -error code is returned on failure
 302  */
 303 static int exfat_find_empty_entry(struct inode *inode,
 304                 struct exfat_chain *p_dir, int num_entries,
 305                 struct exfat_entry_set_cache *es)
 306 {
 307         int dentry;
 308         unsigned int ret, last_clu;
 309         loff_t size = 0;
 310         struct exfat_chain clu;
 311         struct super_block *sb = inode->i_sb;
 312         struct exfat_sb_info *sbi = EXFAT_SB(sb);
 313         struct exfat_inode_info *ei = EXFAT_I(inode);
 314         struct exfat_hint_femp hint_femp;
 315
 316         hint_femp.eidx = EXFAT_HINT_NONE;
 317
 318         if (ei->hint_femp.eidx != EXFAT_HINT_NONE) {
 319                 hint_femp = ei->hint_femp;
 320                 ei->hint_femp.eidx = EXFAT_HINT_NONE;
 321         }
 322
 323         exfat_chain_set(p_dir, ei->start_clu,
 324                         EXFAT_B_TO_CLU(i_size_read(inode), sbi), ei->flags);
 325
 326         while ((dentry = exfat_search_empty_slot(sb, &hint_femp, p_dir,
 327                                         num_entries, es)) < 0) {
 328                 if (dentry != -ENOSPC)
 329                         return dentry;
 330
 331                 if (exfat_check_max_dentries(inode))
 332                         return -ENOSPC;
 333
 334                 /*
 335                  * Allocate new cluster to this directory
 336                  */
 337                 if (ei->start_clu != EXFAT_EOF_CLUSTER) {
 338                         /* we trust p_dir->size regardless of FAT type */
 339                         if (exfat_find_last_cluster(sb, p_dir, &last_clu))
 340                                 return -EIO;
 341
 342                         exfat_chain_set(&clu, last_clu + 1, 0, p_dir->flags);
 343                 } else {
 344                         /* This directory is empty */
 345                         exfat_chain_set(&clu, EXFAT_EOF_CLUSTER, 0,
 346                                         ALLOC_NO_FAT_CHAIN);
 347                 }
 348
 349                 /* allocate a cluster */
 350                 ret = exfat_alloc_cluster(inode, 1, &clu, IS_DIRSYNC(inode));
 351                 if (ret)
 352                         return ret;
 353
 354                 if (exfat_zeroed_cluster(inode, clu.dir))
 355                         return -EIO;
 356
 357                 if (ei->start_clu == EXFAT_EOF_CLUSTER) {
 358                         ei->start_clu = clu.dir;
 359                         p_dir->dir = clu.dir;
 360                         hint_femp.eidx = 0;
 361                 }
 362
 363                 /* append to the FAT chain */
 364                 if (clu.flags != p_dir->flags) {
 365                         /* no-fat-chain bit is disabled,
 366                          * so fat-chain should be synced with alloc-bitmap
 367                          */
 368                         exfat_chain_cont_cluster(sb, p_dir->dir, p_dir->size);
 369                         p_dir->flags = ALLOC_FAT_CHAIN;
 370                         hint_femp.cur.flags = ALLOC_FAT_CHAIN;
 371                 }
 372
 373                 if (clu.flags == ALLOC_FAT_CHAIN)
 374                         if (exfat_ent_set(sb, last_clu, clu.dir))
 375                                 return -EIO;
 376
 377                 if (hint_femp.cur.dir == EXFAT_EOF_CLUSTER)
 378                         exfat_chain_set(&hint_femp.cur, clu.dir, 0, clu.flags);
 379
 380                 hint_femp.count += sbi->dentries_per_clu;
 381
 382                 hint_femp.cur.size++;
 383                 p_dir->size++;
 384                 size = EXFAT_CLU_TO_B(p_dir->size, sbi);
 385
 386                 /* directory inode should be updated in here */
 387                 i_size_write(inode, size);
 388                 ei->valid_size += sbi->cluster_size;
 389                 ei->flags = p_dir->flags;
 390                 inode->i_blocks += sbi->cluster_size >> 9;
 391         }
 392
 393         p_dir->dir = exfat_sector_to_cluster(sbi, es->bh[0]->b_blocknr);
 394         p_dir->size -= dentry / sbi->dentries_per_clu;
 395
 396         return dentry & (sbi->dentries_per_clu - 1);
 397 }
 398
 399 /*
 400  * Name Resolution Functions :
 401  * Zero if it was successful; otherwise nonzero.
 402  */
 403 static int __exfat_resolve_path(struct inode *inode, const unsigned char *path,
 404                 struct exfat_uni_name *p_uniname, int lookup)
 405 {
 406         int namelen;
 407         int lossy = NLS_NAME_NO_LOSSY;
 408         struct super_block *sb = inode->i_sb;
 409         int pathlen = strlen(path);
 410
 411         /*
 412          * get the length of the pathname excluding
 413          * trailing periods, if any.
 414          */
 415         namelen = exfat_striptail_len(pathlen, path, false);
 416         if (EXFAT_SB(sb)->options.keep_last_dots) {
 417                 /*
 418                  * Do not allow the creation of files with names
 419                  * ending with period(s).
 420                  */
 421                 if (!lookup && (namelen < pathlen))
 422                         return -EINVAL;
 423                 namelen = pathlen;
 424         }
 425         if (!namelen)
 426                 return -ENOENT;
 427         if (pathlen > (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 (lossy & NLS_NAME_OVERLEN) ? -ENAMETOOLONG : -EINVAL;
 446
 447         return 0;
 448 }
 449
 450 static inline int exfat_resolve_path(struct inode *inode,
 451                 const unsigned char *path, struct exfat_uni_name *uni)
 452 {
 453         return __exfat_resolve_path(inode, path, uni, 0);
 454 }
 455
 456 static inline int exfat_resolve_path_for_lookup(struct inode *inode,
 457                 const unsigned char *path, struct exfat_uni_name *uni)
 458 {
 459         return __exfat_resolve_path(inode, path, uni, 1);
 460 }
 461
 462 static inline loff_t exfat_make_i_pos(struct exfat_dir_entry *info)
 463 {
 464         return ((loff_t) info->dir.dir << 32) | (info->entry & 0xffffffff);
 465 }
 466
 467 static int exfat_add_entry(struct inode *inode, const char *path,
 468                 unsigned int type, struct exfat_dir_entry *info)
 469 {
 470         int ret, dentry, num_entries;
 471         struct super_block *sb = inode->i_sb;
 472         struct exfat_sb_info *sbi = EXFAT_SB(sb);
 473         struct exfat_uni_name uniname;
 474         struct exfat_chain clu;
 475         struct timespec64 ts = current_time(inode);
 476         struct exfat_entry_set_cache es;
 477         int clu_size = 0;
 478         unsigned int start_clu = EXFAT_FREE_CLUSTER;
 479
 480         ret = exfat_resolve_path(inode, path, &uniname);
 481         if (ret)
 482                 goto out;
 483
 484         num_entries = exfat_calc_num_entries(&uniname);
 485         if (num_entries < 0) {
 486                 ret = num_entries;
 487                 goto out;
 488         }
 489
 490         /* exfat_find_empty_entry must be called before alloc_cluster() */
 491         dentry = exfat_find_empty_entry(inode, &info->dir, num_entries, &es);
 492         if (dentry < 0) {
 493                 ret = dentry; /* -EIO or -ENOSPC */
 494                 goto out;
 495         }
 496
 497         if (type == TYPE_DIR && !sbi->options.zero_size_dir) {
 498                 ret = exfat_alloc_new_dir(inode, &clu);
 499                 if (ret) {
 500                         exfat_put_dentry_set(&es, false);
 501                         goto out;
 502                 }
 503                 start_clu = clu.dir;
 504                 clu_size = sbi->cluster_size;
 505         }
 506
 507         /* update the directory entry */
 508         /* fill the dos name directory entry information of the created file.
 509          * the first cluster is not determined yet. (0)
 510          */
 511         exfat_init_dir_entry(&es, type, start_clu, clu_size, &ts);
 512         exfat_init_ext_entry(&es, num_entries, &uniname);
 513
 514         ret = exfat_put_dentry_set(&es, IS_DIRSYNC(inode));
 515         if (ret)
 516                 goto out;
 517
 518         info->entry = dentry;
 519         info->flags = ALLOC_NO_FAT_CHAIN;
 520         info->type = type;
 521
 522         if (type == TYPE_FILE) {
 523                 info->attr = EXFAT_ATTR_ARCHIVE;
 524                 info->start_clu = EXFAT_EOF_CLUSTER;
 525                 info->size = 0;
 526                 info->num_subdirs = 0;
 527         } else {
 528                 info->attr = EXFAT_ATTR_SUBDIR;
 529                 if (sbi->options.zero_size_dir)
 530                         info->start_clu = EXFAT_EOF_CLUSTER;
 531                 else
 532                         info->start_clu = start_clu;
 533                 info->size = clu_size;
 534                 info->num_subdirs = EXFAT_MIN_SUBDIR;
 535         }
 536         info->valid_size = info->size;
 537
 538         memset(&info->crtime, 0, sizeof(info->crtime));
 539         memset(&info->mtime, 0, sizeof(info->mtime));
 540         memset(&info->atime, 0, sizeof(info->atime));
 541 out:
 542         return ret;
 543 }
 544
 545 static int exfat_create(struct mnt_idmap *idmap, struct inode *dir,
 546                         struct dentry *dentry, umode_t mode, bool excl)
 547 {
 548         struct super_block *sb = dir->i_sb;
 549         struct inode *inode;
 550         struct exfat_dir_entry info;
 551         loff_t i_pos;
 552         int err;
 553         loff_t size = i_size_read(dir);
 554
 555         if (unlikely(exfat_forced_shutdown(sb)))
 556                 return -EIO;
 557
 558         mutex_lock(&EXFAT_SB(sb)->s_lock);
 559         exfat_set_volume_dirty(sb);
 560         err = exfat_add_entry(dir, dentry->d_name.name, TYPE_FILE, &info);
 561         if (err)
 562                 goto unlock;
 563
 564         inode_inc_iversion(dir);
 565         inode_set_mtime_to_ts(dir, inode_set_ctime_current(dir));
 566         if (IS_DIRSYNC(dir) && size != i_size_read(dir))
 567                 exfat_sync_inode(dir);
 568         else
 569                 mark_inode_dirty(dir);
 570
 571         i_pos = exfat_make_i_pos(&info);
 572         inode = exfat_build_inode(sb, &info, i_pos);
 573         err = PTR_ERR_OR_ZERO(inode);
 574         if (err)
 575                 goto unlock;
 576
 577         inode_inc_iversion(inode);
 578         EXFAT_I(inode)->i_crtime = simple_inode_init_ts(inode);
 579         exfat_truncate_inode_atime(inode);
 580
 581         /* timestamp is already written, so mark_inode_dirty() is unneeded. */
 582
 583         d_instantiate(dentry, inode);
 584 unlock:
 585         mutex_unlock(&EXFAT_SB(sb)->s_lock);
 586         return err;
 587 }
 588
 589 /* lookup a file */
 590 static int exfat_find(struct inode *dir, struct qstr *qname,
 591                 struct exfat_dir_entry *info)
 592 {
 593         int ret, dentry, count;
 594         struct exfat_chain cdir;
 595         struct exfat_uni_name uni_name;
 596         struct super_block *sb = dir->i_sb;
 597         struct exfat_sb_info *sbi = EXFAT_SB(sb);
 598         struct exfat_inode_info *ei = EXFAT_I(dir);
 599         struct exfat_dentry *ep, *ep2;
 600         struct exfat_entry_set_cache es;
 601         /* for optimized dir & entry to prevent long traverse of cluster chain */
 602         struct exfat_hint hint_opt;
 603
 604         if (qname->len == 0)
 605                 return -ENOENT;
 606
 607         /* check the validity of directory name in the given pathname */
 608         ret = exfat_resolve_path_for_lookup(dir, qname->name, &uni_name);
 609         if (ret)
 610                 return ret;
 611
 612         exfat_chain_set(&cdir, ei->start_clu,
 613                 EXFAT_B_TO_CLU(i_size_read(dir), sbi), ei->flags);
 614
 615         /* check the validation of hint_stat and initialize it if required */
 616         if (ei->version != (inode_peek_iversion_raw(dir) & 0xffffffff)) {
 617                 ei->hint_stat.clu = cdir.dir;
 618                 ei->hint_stat.eidx = 0;
 619                 ei->version = (inode_peek_iversion_raw(dir) & 0xffffffff);
 620                 ei->hint_femp.eidx = EXFAT_HINT_NONE;
 621         }
 622
 623         /* search the file name for directories */
 624         dentry = exfat_find_dir_entry(sb, ei, &cdir, &uni_name, &hint_opt);
 625         if (dentry < 0)
 626                 return dentry; /* -error value */
 627
 628         /* adjust cdir to the optimized value */
 629         cdir.dir = hint_opt.clu;
 630         if (cdir.flags & ALLOC_NO_FAT_CHAIN)
 631                 cdir.size -= dentry / sbi->dentries_per_clu;
 632         dentry = hint_opt.eidx;
 633
 634         info->dir = cdir;
 635         info->entry = dentry;
 636         info->num_subdirs = 0;
 637
 638         if (exfat_get_dentry_set(&es, sb, &cdir, dentry, ES_2_ENTRIES))
 639                 return -EIO;
 640         ep = exfat_get_dentry_cached(&es, ES_IDX_FILE);
 641         ep2 = exfat_get_dentry_cached(&es, ES_IDX_STREAM);
 642
 643         info->type = exfat_get_entry_type(ep);
 644         info->attr = le16_to_cpu(ep->dentry.file.attr);
 645         info->size = le64_to_cpu(ep2->dentry.stream.valid_size);
 646         info->valid_size = le64_to_cpu(ep2->dentry.stream.valid_size);
 647         info->size = le64_to_cpu(ep2->dentry.stream.size);
 648
 649         if (unlikely(EXFAT_B_TO_CLU_ROUND_UP(info->size, sbi) > sbi->used_clusters)) {
 650                 exfat_fs_error(sb, "data size is invalid(%lld)", info->size);
 651                 return -EIO;
 652         }
 653
 654         info->start_clu = le32_to_cpu(ep2->dentry.stream.start_clu);
 655         if (!is_valid_cluster(sbi, info->start_clu) && info->size) {
 656                 exfat_warn(sb, "start_clu is invalid cluster(0x%x)",
 657                                 info->start_clu);
 658                 info->size = 0;
 659                 info->valid_size = 0;
 660         }
 661
 662         if (info->valid_size > info->size) {
 663                 exfat_warn(sb, "valid_size(%lld) is greater than size(%lld)",
 664                                 info->valid_size, info->size);
 665                 info->valid_size = info->size;
 666         }
 667
 668         if (info->size == 0) {
 669                 info->flags = ALLOC_NO_FAT_CHAIN;
 670                 info->start_clu = EXFAT_EOF_CLUSTER;
 671         } else
 672                 info->flags = ep2->dentry.stream.flags;
 673
 674         exfat_get_entry_time(sbi, &info->crtime,
 675                              ep->dentry.file.create_tz,
 676                              ep->dentry.file.create_time,
 677                              ep->dentry.file.create_date,
 678                              ep->dentry.file.create_time_cs);
 679         exfat_get_entry_time(sbi, &info->mtime,
 680                              ep->dentry.file.modify_tz,
 681                              ep->dentry.file.modify_time,
 682                              ep->dentry.file.modify_date,
 683                              ep->dentry.file.modify_time_cs);
 684         exfat_get_entry_time(sbi, &info->atime,
 685                              ep->dentry.file.access_tz,
 686                              ep->dentry.file.access_time,
 687                              ep->dentry.file.access_date,
 688                              0);
 689         exfat_put_dentry_set(&es, false);
 690
 691         if (ei->start_clu == EXFAT_FREE_CLUSTER) {
 692                 exfat_fs_error(sb,
 693                                "non-zero size file starts with zero cluster (size : %llu, p_dir : %u, entry : 0x%08x)",
 694                                i_size_read(dir), ei->dir.dir, ei->entry);
 695                 return -EIO;
 696         }
 697
 698         if (info->type == TYPE_DIR) {
 699                 exfat_chain_set(&cdir, info->start_clu,
 700                                 EXFAT_B_TO_CLU(info->size, sbi), info->flags);
 701                 count = exfat_count_dir_entries(sb, &cdir);
 702                 if (count < 0)
 703                         return -EIO;
 704
 705                 info->num_subdirs = count + EXFAT_MIN_SUBDIR;
 706         }
 707         return 0;
 708 }
 709
 710 static int exfat_d_anon_disconn(struct dentry *dentry)
 711 {
 712         return IS_ROOT(dentry) && (dentry->d_flags & DCACHE_DISCONNECTED);
 713 }
 714
 715 static struct dentry *exfat_lookup(struct inode *dir, struct dentry *dentry,
 716                 unsigned int flags)
 717 {
 718         struct super_block *sb = dir->i_sb;
 719         struct inode *inode;
 720         struct dentry *alias;
 721         struct exfat_dir_entry info;
 722         int err;
 723         loff_t i_pos;
 724         mode_t i_mode;
 725
 726         mutex_lock(&EXFAT_SB(sb)->s_lock);
 727         err = exfat_find(dir, &dentry->d_name, &info);
 728         if (err) {
 729                 if (err == -ENOENT) {
 730                         inode = NULL;
 731                         goto out;
 732                 }
 733                 goto unlock;
 734         }
 735
 736         i_pos = exfat_make_i_pos(&info);
 737         inode = exfat_build_inode(sb, &info, i_pos);
 738         err = PTR_ERR_OR_ZERO(inode);
 739         if (err)
 740                 goto unlock;
 741
 742         i_mode = inode->i_mode;
 743         alias = d_find_alias(inode);
 744
 745         /*
 746          * Checking "alias->d_parent == dentry->d_parent" to make sure
 747          * FS is not corrupted (especially double linked dir).
 748          */
 749         if (alias && alias->d_parent == dentry->d_parent &&
 750                         !exfat_d_anon_disconn(alias)) {
 751
 752                 /*
 753                  * Unhashed alias is able to exist because of revalidate()
 754                  * called by lookup_fast. You can easily make this status
 755                  * by calling create and lookup concurrently
 756                  * In such case, we reuse an alias instead of new dentry
 757                  */
 758                 if (d_unhashed(alias)) {
 759                         WARN_ON(alias->d_name.hash_len !=
 760                                 dentry->d_name.hash_len);
 761                         exfat_info(sb, "rehashed a dentry(%p) in read lookup",
 762                                    alias);
 763                         d_drop(dentry);
 764                         d_rehash(alias);
 765                 } else if (!S_ISDIR(i_mode)) {
 766                         /*
 767                          * This inode has non anonymous-DCACHE_DISCONNECTED
 768                          * dentry. This means, the user did ->lookup() by an
 769                          * another name (longname vs 8.3 alias of it) in past.
 770                          *
 771                          * Switch to new one for reason of locality if possible.
 772                          */
 773                         d_move(alias, dentry);
 774                 }
 775                 iput(inode);
 776                 mutex_unlock(&EXFAT_SB(sb)->s_lock);
 777                 return alias;
 778         }
 779         dput(alias);
 780 out:
 781         mutex_unlock(&EXFAT_SB(sb)->s_lock);
 782         if (!inode)
 783                 exfat_d_version_set(dentry, inode_query_iversion(dir));
 784
 785         return d_splice_alias(inode, dentry);
 786 unlock:
 787         mutex_unlock(&EXFAT_SB(sb)->s_lock);
 788         return ERR_PTR(err);
 789 }
 790
 791 /* remove an entry, BUT don't truncate */
 792 static int exfat_unlink(struct inode *dir, struct dentry *dentry)
 793 {
 794         struct super_block *sb = dir->i_sb;
 795         struct inode *inode = dentry->d_inode;
 796         struct exfat_inode_info *ei = EXFAT_I(inode);
 797         struct exfat_entry_set_cache es;
 798         int err = 0;
 799
 800         if (unlikely(exfat_forced_shutdown(sb)))
 801                 return -EIO;
 802
 803         mutex_lock(&EXFAT_SB(sb)->s_lock);
 804         if (ei->dir.dir == DIR_DELETED) {
 805                 exfat_err(sb, "abnormal access to deleted dentry");
 806                 err = -ENOENT;
 807                 goto unlock;
 808         }
 809
 810         err = exfat_get_dentry_set_by_ei(&es, sb, ei);
 811         if (err) {
 812                 err = -EIO;
 813                 goto unlock;
 814         }
 815
 816         exfat_set_volume_dirty(sb);
 817
 818         /* update the directory entry */
 819         exfat_remove_entries(inode, &es, ES_IDX_FILE);
 820
 821         err = exfat_put_dentry_set(&es, IS_DIRSYNC(inode));
 822         if (err)
 823                 goto unlock;
 824
 825         /* This doesn't modify ei */
 826         ei->dir.dir = DIR_DELETED;
 827
 828         inode_inc_iversion(dir);
 829         simple_inode_init_ts(dir);
 830         exfat_truncate_inode_atime(dir);
 831         mark_inode_dirty(dir);
 832
 833         clear_nlink(inode);
 834         simple_inode_init_ts(inode);
 835         exfat_truncate_inode_atime(inode);
 836         exfat_unhash_inode(inode);
 837         exfat_d_version_set(dentry, inode_query_iversion(dir));
 838 unlock:
 839         mutex_unlock(&EXFAT_SB(sb)->s_lock);
 840         return err;
 841 }
 842
 843 static struct dentry *exfat_mkdir(struct mnt_idmap *idmap, struct inode *dir,
 844                                   struct dentry *dentry, umode_t mode)
 845 {
 846         struct super_block *sb = dir->i_sb;
 847         struct inode *inode;
 848         struct exfat_dir_entry info;
 849         loff_t i_pos;
 850         int err;
 851         loff_t size = i_size_read(dir);
 852
 853         if (unlikely(exfat_forced_shutdown(sb)))
 854                 return ERR_PTR(-EIO);
 855
 856         mutex_lock(&EXFAT_SB(sb)->s_lock);
 857         exfat_set_volume_dirty(sb);
 858         err = exfat_add_entry(dir, dentry->d_name.name, TYPE_DIR, &info);
 859         if (err)
 860                 goto unlock;
 861
 862         inode_inc_iversion(dir);
 863         inode_set_mtime_to_ts(dir, inode_set_ctime_current(dir));
 864         if (IS_DIRSYNC(dir) && size != i_size_read(dir))
 865                 exfat_sync_inode(dir);
 866         else
 867                 mark_inode_dirty(dir);
 868         inc_nlink(dir);
 869
 870         i_pos = exfat_make_i_pos(&info);
 871         inode = exfat_build_inode(sb, &info, i_pos);
 872         err = PTR_ERR_OR_ZERO(inode);
 873         if (err)
 874                 goto unlock;
 875
 876         inode_inc_iversion(inode);
 877         EXFAT_I(inode)->i_crtime = simple_inode_init_ts(inode);
 878         exfat_truncate_inode_atime(inode);
 879         /* timestamp is already written, so mark_inode_dirty() is unneeded. */
 880
 881         d_instantiate(dentry, inode);
 882
 883 unlock:
 884         mutex_unlock(&EXFAT_SB(sb)->s_lock);
 885         return ERR_PTR(err);
 886 }
 887
 888 static int exfat_check_dir_empty(struct super_block *sb,
 889                 struct exfat_chain *p_dir)
 890 {
 891         int i, dentries_per_clu;
 892         unsigned int type;
 893         struct exfat_chain clu;
 894         struct exfat_dentry *ep;
 895         struct exfat_sb_info *sbi = EXFAT_SB(sb);
 896         struct buffer_head *bh;
 897
 898         dentries_per_clu = sbi->dentries_per_clu;
 899
 900         if (p_dir->dir == EXFAT_EOF_CLUSTER)
 901                 return 0;
 902
 903         exfat_chain_dup(&clu, p_dir);
 904
 905         while (clu.dir != EXFAT_EOF_CLUSTER) {
 906                 for (i = 0; i < dentries_per_clu; i++) {
 907                         ep = exfat_get_dentry(sb, &clu, i, &bh);
 908                         if (!ep)
 909                                 return -EIO;
 910                         type = exfat_get_entry_type(ep);
 911                         brelse(bh);
 912                         if (type == TYPE_UNUSED)
 913                                 return 0;
 914
 915                         if (type != TYPE_FILE && type != TYPE_DIR)
 916                                 continue;
 917
 918                         return -ENOTEMPTY;
 919                 }
 920
 921                 if (clu.flags == ALLOC_NO_FAT_CHAIN) {
 922                         if (--clu.size > 0)
 923                                 clu.dir++;
 924                         else
 925                                 clu.dir = EXFAT_EOF_CLUSTER;
 926                 } else {
 927                         if (exfat_get_next_cluster(sb, &(clu.dir)))
 928                                 return -EIO;
 929                 }
 930         }
 931
 932         return 0;
 933 }
 934
 935 static int exfat_rmdir(struct inode *dir, struct dentry *dentry)
 936 {
 937         struct inode *inode = dentry->d_inode;
 938         struct exfat_chain clu_to_free;
 939         struct super_block *sb = inode->i_sb;
 940         struct exfat_sb_info *sbi = EXFAT_SB(sb);
 941         struct exfat_inode_info *ei = EXFAT_I(inode);
 942         struct exfat_entry_set_cache es;
 943         int err;
 944
 945         if (unlikely(exfat_forced_shutdown(sb)))
 946                 return -EIO;
 947
 948         mutex_lock(&EXFAT_SB(inode->i_sb)->s_lock);
 949
 950         if (ei->dir.dir == DIR_DELETED) {
 951                 exfat_err(sb, "abnormal access to deleted dentry");
 952                 err = -ENOENT;
 953                 goto unlock;
 954         }
 955
 956         exfat_chain_set(&clu_to_free, ei->start_clu,
 957                 EXFAT_B_TO_CLU_ROUND_UP(i_size_read(inode), sbi), ei->flags);
 958
 959         err = exfat_check_dir_empty(sb, &clu_to_free);
 960         if (err) {
 961                 if (err == -EIO)
 962                         exfat_err(sb, "failed to exfat_check_dir_empty : err(%d)",
 963                                   err);
 964                 goto unlock;
 965         }
 966
 967         err = exfat_get_dentry_set_by_ei(&es, sb, ei);
 968         if (err) {
 969                 err = -EIO;
 970                 goto unlock;
 971         }
 972
 973         exfat_set_volume_dirty(sb);
 974
 975         exfat_remove_entries(inode, &es, ES_IDX_FILE);
 976
 977         err = exfat_put_dentry_set(&es, IS_DIRSYNC(dir));
 978         if (err)
 979                 goto unlock;
 980
 981         ei->dir.dir = DIR_DELETED;
 982
 983         inode_inc_iversion(dir);
 984         simple_inode_init_ts(dir);
 985         exfat_truncate_inode_atime(dir);
 986         if (IS_DIRSYNC(dir))
 987                 exfat_sync_inode(dir);
 988         else
 989                 mark_inode_dirty(dir);
 990         drop_nlink(dir);
 991
 992         clear_nlink(inode);
 993         simple_inode_init_ts(inode);
 994         exfat_truncate_inode_atime(inode);
 995         exfat_unhash_inode(inode);
 996         exfat_d_version_set(dentry, inode_query_iversion(dir));
 997 unlock:
 998         mutex_unlock(&EXFAT_SB(inode->i_sb)->s_lock);
 999         return err;
1000 }
1001
1002 static int exfat_rename_file(struct inode *parent_inode,
1003                 struct exfat_uni_name *p_uniname, struct exfat_inode_info *ei)
1004 {
1005         int ret, num_new_entries;
1006         struct exfat_dentry *epold, *epnew;
1007         struct super_block *sb = parent_inode->i_sb;
1008         struct exfat_entry_set_cache old_es, new_es;
1009         int sync = IS_DIRSYNC(parent_inode);
1010
1011         if (unlikely(exfat_forced_shutdown(sb)))
1012                 return -EIO;
1013
1014         num_new_entries = exfat_calc_num_entries(p_uniname);
1015         if (num_new_entries < 0)
1016                 return num_new_entries;
1017
1018         ret = exfat_get_dentry_set_by_ei(&old_es, sb, ei);
1019         if (ret) {
1020                 ret = -EIO;
1021                 return ret;
1022         }
1023
1024         epold = exfat_get_dentry_cached(&old_es, ES_IDX_FILE);
1025
1026         if (old_es.num_entries < num_new_entries) {
1027                 int newentry;
1028                 struct exfat_chain dir;
1029
1030                 newentry = exfat_find_empty_entry(parent_inode, &dir,
1031                                 num_new_entries, &new_es);
1032                 if (newentry < 0) {
1033                         ret = newentry; /* -EIO or -ENOSPC */
1034                         goto put_old_es;
1035                 }
1036
1037                 epnew = exfat_get_dentry_cached(&new_es, ES_IDX_FILE);
1038                 *epnew = *epold;
1039                 if (exfat_get_entry_type(epnew) == TYPE_FILE) {
1040                         epnew->dentry.file.attr |= cpu_to_le16(EXFAT_ATTR_ARCHIVE);
1041                         ei->attr |= EXFAT_ATTR_ARCHIVE;
1042                 }
1043
1044                 epold = exfat_get_dentry_cached(&old_es, ES_IDX_STREAM);
1045                 epnew = exfat_get_dentry_cached(&new_es, ES_IDX_STREAM);
1046                 *epnew = *epold;
1047
1048                 exfat_init_ext_entry(&new_es, num_new_entries, p_uniname);
1049
1050                 ret = exfat_put_dentry_set(&new_es, sync);
1051                 if (ret)
1052                         goto put_old_es;
1053
1054                 exfat_remove_entries(parent_inode, &old_es, ES_IDX_FILE);
1055                 ei->dir = dir;
1056                 ei->entry = newentry;
1057         } else {
1058                 if (exfat_get_entry_type(epold) == TYPE_FILE) {
1059                         epold->dentry.file.attr |= cpu_to_le16(EXFAT_ATTR_ARCHIVE);
1060                         ei->attr |= EXFAT_ATTR_ARCHIVE;
1061                 }
1062
1063                 exfat_remove_entries(parent_inode, &old_es, ES_IDX_FIRST_FILENAME + 1);
1064                 exfat_init_ext_entry(&old_es, num_new_entries, p_uniname);
1065         }
1066         return exfat_put_dentry_set(&old_es, sync);
1067
1068 put_old_es:
1069         exfat_put_dentry_set(&old_es, false);
1070         return ret;
1071 }
1072
1073 static int exfat_move_file(struct inode *parent_inode,
1074                 struct exfat_uni_name *p_uniname, struct exfat_inode_info *ei)
1075 {
1076         int ret, newentry, num_new_entries;
1077         struct exfat_dentry *epmov, *epnew;
1078         struct exfat_entry_set_cache mov_es, new_es;
1079         struct exfat_chain newdir;
1080
1081         num_new_entries = exfat_calc_num_entries(p_uniname);
1082         if (num_new_entries < 0)
1083                 return num_new_entries;
1084
1085         ret = exfat_get_dentry_set_by_ei(&mov_es, parent_inode->i_sb, ei);
1086         if (ret)
1087                 return -EIO;
1088
1089         newentry = exfat_find_empty_entry(parent_inode, &newdir,
1090                         num_new_entries, &new_es);
1091         if (newentry < 0) {
1092                 ret = newentry; /* -EIO or -ENOSPC */
1093                 goto put_mov_es;
1094         }
1095
1096         epmov = exfat_get_dentry_cached(&mov_es, ES_IDX_FILE);
1097         epnew = exfat_get_dentry_cached(&new_es, ES_IDX_FILE);
1098         *epnew = *epmov;
1099         if (exfat_get_entry_type(epnew) == TYPE_FILE) {
1100                 epnew->dentry.file.attr |= cpu_to_le16(EXFAT_ATTR_ARCHIVE);
1101                 ei->attr |= EXFAT_ATTR_ARCHIVE;
1102         }
1103
1104         epmov = exfat_get_dentry_cached(&mov_es, ES_IDX_STREAM);
1105         epnew = exfat_get_dentry_cached(&new_es, ES_IDX_STREAM);
1106         *epnew = *epmov;
1107
1108         exfat_init_ext_entry(&new_es, num_new_entries, p_uniname);
1109         exfat_remove_entries(parent_inode, &mov_es, ES_IDX_FILE);
1110
1111         ei->dir = newdir;
1112         ei->entry = newentry;
1113
1114         ret = exfat_put_dentry_set(&new_es, IS_DIRSYNC(parent_inode));
1115         if (ret)
1116                 goto put_mov_es;
1117
1118         return exfat_put_dentry_set(&mov_es, IS_DIRSYNC(parent_inode));
1119
1120 put_mov_es:
1121         exfat_put_dentry_set(&mov_es, false);
1122
1123         return ret;
1124 }
1125
1126 /* rename or move a old file into a new file */
1127 static int __exfat_rename(struct inode *old_parent_inode,
1128                 struct exfat_inode_info *ei, struct inode *new_parent_inode,
1129                 struct dentry *new_dentry)
1130 {
1131         int ret;
1132         struct exfat_uni_name uni_name;
1133         struct super_block *sb = old_parent_inode->i_sb;
1134         struct exfat_sb_info *sbi = EXFAT_SB(sb);
1135         const unsigned char *new_path = new_dentry->d_name.name;
1136         struct inode *new_inode = new_dentry->d_inode;
1137         struct exfat_inode_info *new_ei = NULL;
1138
1139         /* check the validity of pointer parameters */
1140         if (new_path == NULL || strlen(new_path) == 0)
1141                 return -EINVAL;
1142
1143         if (ei->dir.dir == DIR_DELETED) {
1144                 exfat_err(sb, "abnormal access to deleted source dentry");
1145                 return -ENOENT;
1146         }
1147
1148         /* check whether new dir is existing directory and empty */
1149         if (new_inode) {
1150                 ret = -EIO;
1151                 new_ei = EXFAT_I(new_inode);
1152
1153                 if (new_ei->dir.dir == DIR_DELETED) {
1154                         exfat_err(sb, "abnormal access to deleted target dentry");
1155                         goto out;
1156                 }
1157
1158                 /* if new_inode exists, update ei */
1159                 if (S_ISDIR(new_inode->i_mode)) {
1160                         struct exfat_chain new_clu;
1161
1162                         new_clu.dir = new_ei->start_clu;
1163                         new_clu.size =
1164                                 EXFAT_B_TO_CLU_ROUND_UP(i_size_read(new_inode),
1165                                 sbi);
1166                         new_clu.flags = new_ei->flags;
1167
1168                         ret = exfat_check_dir_empty(sb, &new_clu);
1169                         if (ret)
1170                                 goto out;
1171                 }
1172         }
1173
1174         /* check the validity of directory name in the given new pathname */
1175         ret = exfat_resolve_path(new_parent_inode, new_path, &uni_name);
1176         if (ret)
1177                 goto out;
1178
1179         exfat_set_volume_dirty(sb);
1180
1181         if (new_parent_inode == old_parent_inode)
1182                 ret = exfat_rename_file(new_parent_inode, &uni_name, ei);
1183         else
1184                 ret = exfat_move_file(new_parent_inode, &uni_name, ei);
1185
1186         if (!ret && new_inode) {
1187                 struct exfat_entry_set_cache es;
1188
1189                 /* delete entries of new_dir */
1190                 ret = exfat_get_dentry_set_by_ei(&es, sb, new_ei);
1191                 if (ret) {
1192                         ret = -EIO;
1193                         goto del_out;
1194                 }
1195
1196                 exfat_remove_entries(new_inode, &es, ES_IDX_FILE);
1197
1198                 ret = exfat_put_dentry_set(&es, IS_DIRSYNC(new_inode));
1199                 if (ret)
1200                         goto del_out;
1201
1202                 /* Free the clusters if new_inode is a dir(as if exfat_rmdir) */
1203                 if (S_ISDIR(new_inode->i_mode) &&
1204                     new_ei->start_clu != EXFAT_EOF_CLUSTER) {
1205                         /* new_ei, new_clu_to_free */
1206                         struct exfat_chain new_clu_to_free;
1207
1208                         exfat_chain_set(&new_clu_to_free, new_ei->start_clu,
1209                                 EXFAT_B_TO_CLU_ROUND_UP(i_size_read(new_inode),
1210                                 sbi), new_ei->flags);
1211
1212                         if (exfat_free_cluster(new_inode, &new_clu_to_free)) {
1213                                 /* just set I/O error only */
1214                                 ret = -EIO;
1215                         }
1216
1217                         i_size_write(new_inode, 0);
1218                         new_ei->valid_size = 0;
1219                         new_ei->start_clu = EXFAT_EOF_CLUSTER;
1220                         new_ei->flags = ALLOC_NO_FAT_CHAIN;
1221                 }
1222 del_out:
1223                 /* Update new_inode ei
1224                  * Prevent syncing removed new_inode
1225                  * (new_ei is already initialized above code ("if (new_inode)")
1226                  */
1227                 new_ei->dir.dir = DIR_DELETED;
1228         }
1229 out:
1230         return ret;
1231 }
1232
1233 static int exfat_rename(struct mnt_idmap *idmap,
1234                         struct inode *old_dir, struct dentry *old_dentry,
1235                         struct inode *new_dir, struct dentry *new_dentry,
1236                         unsigned int flags)
1237 {
1238         struct inode *old_inode, *new_inode;
1239         struct super_block *sb = old_dir->i_sb;
1240         loff_t i_pos;
1241         int err;
1242         loff_t size = i_size_read(new_dir);
1243
1244         /*
1245          * The VFS already checks for existence, so for local filesystems
1246          * the RENAME_NOREPLACE implementation is equivalent to plain rename.
1247          * Don't support any other flags
1248          */
1249         if (flags & ~RENAME_NOREPLACE)
1250                 return -EINVAL;
1251
1252         mutex_lock(&EXFAT_SB(sb)->s_lock);
1253         old_inode = old_dentry->d_inode;
1254         new_inode = new_dentry->d_inode;
1255
1256         err = __exfat_rename(old_dir, EXFAT_I(old_inode), new_dir, new_dentry);
1257         if (err)
1258                 goto unlock;
1259
1260         inode_inc_iversion(new_dir);
1261         simple_rename_timestamp(old_dir, old_dentry, new_dir, new_dentry);
1262         EXFAT_I(new_dir)->i_crtime = current_time(new_dir);
1263         exfat_truncate_inode_atime(new_dir);
1264         if (IS_DIRSYNC(new_dir) && size != i_size_read(new_dir))
1265                 exfat_sync_inode(new_dir);
1266         else
1267                 mark_inode_dirty(new_dir);
1268
1269         i_pos = ((loff_t)EXFAT_I(old_inode)->dir.dir << 32) |
1270                 (EXFAT_I(old_inode)->entry & 0xffffffff);
1271         exfat_unhash_inode(old_inode);
1272         exfat_hash_inode(old_inode, i_pos);
1273         if (IS_DIRSYNC(new_dir))
1274                 exfat_sync_inode(old_inode);
1275         else
1276                 mark_inode_dirty(old_inode);
1277
1278         if (S_ISDIR(old_inode->i_mode) && old_dir != new_dir) {
1279                 drop_nlink(old_dir);
1280                 if (!new_inode)
1281                         inc_nlink(new_dir);
1282         }
1283
1284         inode_inc_iversion(old_dir);
1285         if (new_dir != old_dir)
1286                 mark_inode_dirty(old_dir);
1287
1288         if (new_inode) {
1289                 exfat_unhash_inode(new_inode);
1290
1291                 /* skip drop_nlink if new_inode already has been dropped */
1292                 if (new_inode->i_nlink) {
1293                         drop_nlink(new_inode);
1294                         if (S_ISDIR(new_inode->i_mode))
1295                                 drop_nlink(new_inode);
1296                 } else {
1297                         exfat_warn(sb, "abnormal access to an inode dropped");
1298                         WARN_ON(new_inode->i_nlink == 0);
1299                 }
1300                 EXFAT_I(new_inode)->i_crtime = current_time(new_inode);
1301         }
1302
1303 unlock:
1304         mutex_unlock(&EXFAT_SB(sb)->s_lock);
1305         return err;
1306 }
1307
1308 const struct inode_operations exfat_dir_inode_operations = {
1309         .create         = exfat_create,
1310         .lookup         = exfat_lookup,
1311         .unlink         = exfat_unlink,
1312         .mkdir          = exfat_mkdir,
1313         .rmdir          = exfat_rmdir,
1314         .rename         = exfat_rename,
1315         .setattr        = exfat_setattr,
1316         .getattr        = exfat_getattr,
1317 };