fs/exfat/dir.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/slab.h>
   7 #include <linux/compat.h>
   8 #include <linux/bio.h>
   9 #include <linux/buffer_head.h>
  10
  11 #include "exfat_raw.h"
  12 #include "exfat_fs.h"
  13
  14 static int exfat_extract_uni_name(struct exfat_dentry *ep,
  15                 unsigned short *uniname)
  16 {
  17         int i, len = 0;
  18
  19         for (i = 0; i < EXFAT_FILE_NAME_LEN; i++) {
  20                 *uniname = le16_to_cpu(ep->dentry.name.unicode_0_14[i]);
  21                 if (*uniname == 0x0)
  22                         return len;
  23                 uniname++;
  24                 len++;
  25         }
  26
  27         *uniname = 0x0;
  28         return len;
  29
  30 }
  31
  32 static int exfat_get_uniname_from_ext_entry(struct super_block *sb,
  33                 struct exfat_chain *p_dir, int entry, unsigned short *uniname)
  34 {
  35         int i, err;
  36         struct exfat_entry_set_cache es;
  37
  38         err = exfat_get_dentry_set(&es, sb, p_dir, entry, ES_ALL_ENTRIES);
  39         if (err)
  40                 return err;
  41
  42         /*
  43          * First entry  : file entry
  44          * Second entry : stream-extension entry
  45          * Third entry  : first file-name entry
  46          * So, the index of first file-name dentry should start from 2.
  47          */
  48         for (i = ES_IDX_FIRST_FILENAME; i < es.num_entries; i++) {
  49                 struct exfat_dentry *ep = exfat_get_dentry_cached(&es, i);
  50
  51                 /* end of name entry */
  52                 if (exfat_get_entry_type(ep) != TYPE_EXTEND)
  53                         break;
  54
  55                 exfat_extract_uni_name(ep, uniname);
  56                 uniname += EXFAT_FILE_NAME_LEN;
  57         }
  58
  59         exfat_put_dentry_set(&es, false);
  60         return 0;
  61 }
  62
  63 /* read a directory entry from the opened directory */
  64 static int exfat_readdir(struct inode *inode, loff_t *cpos, struct exfat_dir_entry *dir_entry)
  65 {
  66         int i, dentries_per_clu, num_ext, err;
  67         unsigned int type, clu_offset, max_dentries;
  68         struct exfat_chain dir, clu;
  69         struct exfat_uni_name uni_name;
  70         struct exfat_dentry *ep;
  71         struct super_block *sb = inode->i_sb;
  72         struct exfat_sb_info *sbi = EXFAT_SB(sb);
  73         struct exfat_inode_info *ei = EXFAT_I(inode);
  74         unsigned int dentry = EXFAT_B_TO_DEN(*cpos) & 0xFFFFFFFF;
  75         struct buffer_head *bh;
  76
  77         /* check if the given file ID is opened */
  78         if (ei->type != TYPE_DIR)
  79                 return -EPERM;
  80
  81         if (ei->entry == -1)
  82                 exfat_chain_set(&dir, sbi->root_dir, 0, ALLOC_FAT_CHAIN);
  83         else
  84                 exfat_chain_set(&dir, ei->start_clu,
  85                         EXFAT_B_TO_CLU(i_size_read(inode), sbi), ei->flags);
  86
  87         dentries_per_clu = sbi->dentries_per_clu;
  88         max_dentries = (unsigned int)min_t(u64, MAX_EXFAT_DENTRIES,
  89                                 (u64)EXFAT_CLU_TO_DEN(sbi->num_clusters, sbi));
  90
  91         clu_offset = EXFAT_DEN_TO_CLU(dentry, sbi);
  92         exfat_chain_dup(&clu, &dir);
  93
  94         if (clu.flags == ALLOC_NO_FAT_CHAIN) {
  95                 clu.dir += clu_offset;
  96                 clu.size -= clu_offset;
  97         } else {
  98                 /* hint_information */
  99                 if (clu_offset > 0 && ei->hint_bmap.off != EXFAT_EOF_CLUSTER &&
 100                     ei->hint_bmap.off > 0 && clu_offset >= ei->hint_bmap.off) {
 101                         clu_offset -= ei->hint_bmap.off;
 102                         clu.dir = ei->hint_bmap.clu;
 103                 }
 104
 105                 while (clu_offset > 0 && clu.dir != EXFAT_EOF_CLUSTER) {
 106                         if (exfat_get_next_cluster(sb, &(clu.dir)))
 107                                 return -EIO;
 108
 109                         clu_offset--;
 110                 }
 111         }
 112
 113         while (clu.dir != EXFAT_EOF_CLUSTER && dentry < max_dentries) {
 114                 i = dentry & (dentries_per_clu - 1);
 115
 116                 for ( ; i < dentries_per_clu; i++, dentry++) {
 117                         ep = exfat_get_dentry(sb, &clu, i, &bh);
 118                         if (!ep)
 119                                 return -EIO;
 120
 121                         type = exfat_get_entry_type(ep);
 122                         if (type == TYPE_UNUSED) {
 123                                 brelse(bh);
 124                                 break;
 125                         }
 126
 127                         if (type != TYPE_FILE && type != TYPE_DIR) {
 128                                 brelse(bh);
 129                                 continue;
 130                         }
 131
 132                         num_ext = ep->dentry.file.num_ext;
 133                         dir_entry->attr = le16_to_cpu(ep->dentry.file.attr);
 134                         exfat_get_entry_time(sbi, &dir_entry->crtime,
 135                                         ep->dentry.file.create_tz,
 136                                         ep->dentry.file.create_time,
 137                                         ep->dentry.file.create_date,
 138                                         ep->dentry.file.create_time_cs);
 139                         exfat_get_entry_time(sbi, &dir_entry->mtime,
 140                                         ep->dentry.file.modify_tz,
 141                                         ep->dentry.file.modify_time,
 142                                         ep->dentry.file.modify_date,
 143                                         ep->dentry.file.modify_time_cs);
 144                         exfat_get_entry_time(sbi, &dir_entry->atime,
 145                                         ep->dentry.file.access_tz,
 146                                         ep->dentry.file.access_time,
 147                                         ep->dentry.file.access_date,
 148                                         0);
 149
 150                         *uni_name.name = 0x0;
 151                         err = exfat_get_uniname_from_ext_entry(sb, &clu, i,
 152                                 uni_name.name);
 153                         if (err) {
 154                                 brelse(bh);
 155                                 continue;
 156                         }
 157                         exfat_utf16_to_nls(sb, &uni_name,
 158                                 dir_entry->namebuf.lfn,
 159                                 dir_entry->namebuf.lfnbuf_len);
 160                         brelse(bh);
 161
 162                         ep = exfat_get_dentry(sb, &clu, i + 1, &bh);
 163                         if (!ep)
 164                                 return -EIO;
 165                         dir_entry->size =
 166                                 le64_to_cpu(ep->dentry.stream.valid_size);
 167                         dir_entry->entry = dentry;
 168                         brelse(bh);
 169
 170                         ei->hint_bmap.off = EXFAT_DEN_TO_CLU(dentry, sbi);
 171                         ei->hint_bmap.clu = clu.dir;
 172
 173                         *cpos = EXFAT_DEN_TO_B(dentry + 1 + num_ext);
 174                         return 0;
 175                 }
 176
 177                 if (clu.flags == ALLOC_NO_FAT_CHAIN) {
 178                         if (--clu.size > 0)
 179                                 clu.dir++;
 180                         else
 181                                 clu.dir = EXFAT_EOF_CLUSTER;
 182                 } else {
 183                         if (exfat_get_next_cluster(sb, &(clu.dir)))
 184                                 return -EIO;
 185                 }
 186         }
 187
 188         dir_entry->namebuf.lfn[0] = '\0';
 189         *cpos = EXFAT_DEN_TO_B(dentry);
 190         return 0;
 191 }
 192
 193 static void exfat_init_namebuf(struct exfat_dentry_namebuf *nb)
 194 {
 195         nb->lfn = NULL;
 196         nb->lfnbuf_len = 0;
 197 }
 198
 199 static int exfat_alloc_namebuf(struct exfat_dentry_namebuf *nb)
 200 {
 201         nb->lfn = __getname();
 202         if (!nb->lfn)
 203                 return -ENOMEM;
 204         nb->lfnbuf_len = MAX_VFSNAME_BUF_SIZE;
 205         return 0;
 206 }
 207
 208 static void exfat_free_namebuf(struct exfat_dentry_namebuf *nb)
 209 {
 210         if (!nb->lfn)
 211                 return;
 212
 213         __putname(nb->lfn);
 214         exfat_init_namebuf(nb);
 215 }
 216
 217 /* skip iterating emit_dots when dir is empty */
 218 #define ITER_POS_FILLED_DOTS    (2)
 219 static int exfat_iterate(struct file *file, struct dir_context *ctx)
 220 {
 221         struct inode *inode = file_inode(file);
 222         struct super_block *sb = inode->i_sb;
 223         struct inode *tmp;
 224         struct exfat_dir_entry de;
 225         struct exfat_dentry_namebuf *nb = &(de.namebuf);
 226         struct exfat_inode_info *ei = EXFAT_I(inode);
 227         unsigned long inum;
 228         loff_t cpos, i_pos;
 229         int err = 0, fake_offset = 0;
 230
 231         exfat_init_namebuf(nb);
 232         mutex_lock(&EXFAT_SB(sb)->s_lock);
 233
 234         cpos = ctx->pos;
 235         if (!dir_emit_dots(file, ctx))
 236                 goto unlock;
 237
 238         if (ctx->pos == ITER_POS_FILLED_DOTS) {
 239                 cpos = 0;
 240                 fake_offset = 1;
 241         }
 242
 243         cpos = round_up(cpos, DENTRY_SIZE);
 244
 245         /* name buffer should be allocated before use */
 246         err = exfat_alloc_namebuf(nb);
 247         if (err)
 248                 goto unlock;
 249 get_new:
 250         if (ei->flags == ALLOC_NO_FAT_CHAIN && cpos >= i_size_read(inode))
 251                 goto end_of_dir;
 252
 253         err = exfat_readdir(inode, &cpos, &de);
 254         if (err) {
 255                 /*
 256                  * At least we tried to read a sector.  Move cpos to next sector
 257                  * position (should be aligned).
 258                  */
 259                 if (err == -EIO) {
 260                         cpos += 1 << (sb->s_blocksize_bits);
 261                         cpos &= ~(sb->s_blocksize - 1);
 262                 }
 263
 264                 err = -EIO;
 265                 goto end_of_dir;
 266         }
 267
 268         if (!nb->lfn[0])
 269                 goto end_of_dir;
 270
 271         i_pos = ((loff_t)ei->start_clu << 32) | (de.entry & 0xffffffff);
 272         tmp = exfat_iget(sb, i_pos);
 273         if (tmp) {
 274                 inum = tmp->i_ino;
 275                 iput(tmp);
 276         } else {
 277                 inum = iunique(sb, EXFAT_ROOT_INO);
 278         }
 279
 280         /*
 281          * Before calling dir_emit(), sb_lock should be released.
 282          * Because page fault can occur in dir_emit() when the size
 283          * of buffer given from user is larger than one page size.
 284          */
 285         mutex_unlock(&EXFAT_SB(sb)->s_lock);
 286         if (!dir_emit(ctx, nb->lfn, strlen(nb->lfn), inum,
 287                         (de.attr & ATTR_SUBDIR) ? DT_DIR : DT_REG))
 288                 goto out_unlocked;
 289         mutex_lock(&EXFAT_SB(sb)->s_lock);
 290         ctx->pos = cpos;
 291         goto get_new;
 292
 293 end_of_dir:
 294         if (!cpos && fake_offset)
 295                 cpos = ITER_POS_FILLED_DOTS;
 296         ctx->pos = cpos;
 297 unlock:
 298         mutex_unlock(&EXFAT_SB(sb)->s_lock);
 299 out_unlocked:
 300         /*
 301          * To improve performance, free namebuf after unlock sb_lock.
 302          * If namebuf is not allocated, this function do nothing
 303          */
 304         exfat_free_namebuf(nb);
 305         return err;
 306 }
 307
 308 const struct file_operations exfat_dir_operations = {
 309         .llseek         = generic_file_llseek,
 310         .read           = generic_read_dir,
 311         .iterate        = exfat_iterate,
 312         .unlocked_ioctl = exfat_ioctl,
 313 #ifdef CONFIG_COMPAT
 314         .compat_ioctl = exfat_compat_ioctl,
 315 #endif
 316         .fsync          = exfat_file_fsync,
 317 };
 318
 319 int exfat_alloc_new_dir(struct inode *inode, struct exfat_chain *clu)
 320 {
 321         int ret;
 322
 323         exfat_chain_set(clu, EXFAT_EOF_CLUSTER, 0, ALLOC_NO_FAT_CHAIN);
 324
 325         ret = exfat_alloc_cluster(inode, 1, clu, IS_DIRSYNC(inode));
 326         if (ret)
 327                 return ret;
 328
 329         return exfat_zeroed_cluster(inode, clu->dir);
 330 }
 331
 332 int exfat_calc_num_entries(struct exfat_uni_name *p_uniname)
 333 {
 334         int len;
 335
 336         len = p_uniname->name_len;
 337         if (len == 0)
 338                 return -EINVAL;
 339
 340         /* 1 file entry + 1 stream entry + name entries */
 341         return ES_ENTRY_NUM(len);
 342 }
 343
 344 unsigned int exfat_get_entry_type(struct exfat_dentry *ep)
 345 {
 346         if (ep->type == EXFAT_UNUSED)
 347                 return TYPE_UNUSED;
 348         if (IS_EXFAT_DELETED(ep->type))
 349                 return TYPE_DELETED;
 350         if (ep->type == EXFAT_INVAL)
 351                 return TYPE_INVALID;
 352         if (IS_EXFAT_CRITICAL_PRI(ep->type)) {
 353                 if (ep->type == EXFAT_BITMAP)
 354                         return TYPE_BITMAP;
 355                 if (ep->type == EXFAT_UPCASE)
 356                         return TYPE_UPCASE;
 357                 if (ep->type == EXFAT_VOLUME)
 358                         return TYPE_VOLUME;
 359                 if (ep->type == EXFAT_FILE) {
 360                         if (le16_to_cpu(ep->dentry.file.attr) & ATTR_SUBDIR)
 361                                 return TYPE_DIR;
 362                         return TYPE_FILE;
 363                 }
 364                 return TYPE_CRITICAL_PRI;
 365         }
 366         if (IS_EXFAT_BENIGN_PRI(ep->type)) {
 367                 if (ep->type == EXFAT_GUID)
 368                         return TYPE_GUID;
 369                 if (ep->type == EXFAT_PADDING)
 370                         return TYPE_PADDING;
 371                 if (ep->type == EXFAT_ACLTAB)
 372                         return TYPE_ACLTAB;
 373                 return TYPE_BENIGN_PRI;
 374         }
 375         if (IS_EXFAT_CRITICAL_SEC(ep->type)) {
 376                 if (ep->type == EXFAT_STREAM)
 377                         return TYPE_STREAM;
 378                 if (ep->type == EXFAT_NAME)
 379                         return TYPE_EXTEND;
 380                 if (ep->type == EXFAT_ACL)
 381                         return TYPE_ACL;
 382                 return TYPE_CRITICAL_SEC;
 383         }
 384
 385         if (ep->type == EXFAT_VENDOR_EXT)
 386                 return TYPE_VENDOR_EXT;
 387         if (ep->type == EXFAT_VENDOR_ALLOC)
 388                 return TYPE_VENDOR_ALLOC;
 389
 390         return TYPE_BENIGN_SEC;
 391 }
 392
 393 static void exfat_set_entry_type(struct exfat_dentry *ep, unsigned int type)
 394 {
 395         if (type == TYPE_UNUSED) {
 396                 ep->type = EXFAT_UNUSED;
 397         } else if (type == TYPE_DELETED) {
 398                 ep->type &= EXFAT_DELETE;
 399         } else if (type == TYPE_STREAM) {
 400                 ep->type = EXFAT_STREAM;
 401         } else if (type == TYPE_EXTEND) {
 402                 ep->type = EXFAT_NAME;
 403         } else if (type == TYPE_BITMAP) {
 404                 ep->type = EXFAT_BITMAP;
 405         } else if (type == TYPE_UPCASE) {
 406                 ep->type = EXFAT_UPCASE;
 407         } else if (type == TYPE_VOLUME) {
 408                 ep->type = EXFAT_VOLUME;
 409         } else if (type == TYPE_DIR) {
 410                 ep->type = EXFAT_FILE;
 411                 ep->dentry.file.attr = cpu_to_le16(ATTR_SUBDIR);
 412         } else if (type == TYPE_FILE) {
 413                 ep->type = EXFAT_FILE;
 414                 ep->dentry.file.attr = cpu_to_le16(ATTR_ARCHIVE);
 415         }
 416 }
 417
 418 static void exfat_init_stream_entry(struct exfat_dentry *ep,
 419                 unsigned char flags, unsigned int start_clu,
 420                 unsigned long long size)
 421 {
 422         exfat_set_entry_type(ep, TYPE_STREAM);
 423         ep->dentry.stream.flags = flags;
 424         ep->dentry.stream.start_clu = cpu_to_le32(start_clu);
 425         ep->dentry.stream.valid_size = cpu_to_le64(size);
 426         ep->dentry.stream.size = cpu_to_le64(size);
 427 }
 428
 429 static void exfat_init_name_entry(struct exfat_dentry *ep,
 430                 unsigned short *uniname)
 431 {
 432         int i;
 433
 434         exfat_set_entry_type(ep, TYPE_EXTEND);
 435         ep->dentry.name.flags = 0x0;
 436
 437         for (i = 0; i < EXFAT_FILE_NAME_LEN; i++) {
 438                 if (*uniname != 0x0) {
 439                         ep->dentry.name.unicode_0_14[i] = cpu_to_le16(*uniname);
 440                         uniname++;
 441                 } else {
 442                         ep->dentry.name.unicode_0_14[i] = 0x0;
 443                 }
 444         }
 445 }
 446
 447 int exfat_init_dir_entry(struct inode *inode, struct exfat_chain *p_dir,
 448                 int entry, unsigned int type, unsigned int start_clu,
 449                 unsigned long long size)
 450 {
 451         struct super_block *sb = inode->i_sb;
 452         struct exfat_sb_info *sbi = EXFAT_SB(sb);
 453         struct timespec64 ts = current_time(inode);
 454         struct exfat_dentry *ep;
 455         struct buffer_head *bh;
 456
 457         /*
 458          * We cannot use exfat_get_dentry_set here because file ep is not
 459          * initialized yet.
 460          */
 461         ep = exfat_get_dentry(sb, p_dir, entry, &bh);
 462         if (!ep)
 463                 return -EIO;
 464
 465         exfat_set_entry_type(ep, type);
 466         exfat_set_entry_time(sbi, &ts,
 467                         &ep->dentry.file.create_tz,
 468                         &ep->dentry.file.create_time,
 469                         &ep->dentry.file.create_date,
 470                         &ep->dentry.file.create_time_cs);
 471         exfat_set_entry_time(sbi, &ts,
 472                         &ep->dentry.file.modify_tz,
 473                         &ep->dentry.file.modify_time,
 474                         &ep->dentry.file.modify_date,
 475                         &ep->dentry.file.modify_time_cs);
 476         exfat_set_entry_time(sbi, &ts,
 477                         &ep->dentry.file.access_tz,
 478                         &ep->dentry.file.access_time,
 479                         &ep->dentry.file.access_date,
 480                         NULL);
 481
 482         exfat_update_bh(bh, IS_DIRSYNC(inode));
 483         brelse(bh);
 484
 485         ep = exfat_get_dentry(sb, p_dir, entry + 1, &bh);
 486         if (!ep)
 487                 return -EIO;
 488
 489         exfat_init_stream_entry(ep,
 490                 (type == TYPE_FILE) ? ALLOC_FAT_CHAIN : ALLOC_NO_FAT_CHAIN,
 491                 start_clu, size);
 492         exfat_update_bh(bh, IS_DIRSYNC(inode));
 493         brelse(bh);
 494
 495         return 0;
 496 }
 497
 498 int exfat_update_dir_chksum(struct inode *inode, struct exfat_chain *p_dir,
 499                 int entry)
 500 {
 501         struct super_block *sb = inode->i_sb;
 502         int ret = 0;
 503         int i, num_entries;
 504         u16 chksum;
 505         struct exfat_dentry *ep, *fep;
 506         struct buffer_head *fbh, *bh;
 507
 508         fep = exfat_get_dentry(sb, p_dir, entry, &fbh);
 509         if (!fep)
 510                 return -EIO;
 511
 512         num_entries = fep->dentry.file.num_ext + 1;
 513         chksum = exfat_calc_chksum16(fep, DENTRY_SIZE, 0, CS_DIR_ENTRY);
 514
 515         for (i = 1; i < num_entries; i++) {
 516                 ep = exfat_get_dentry(sb, p_dir, entry + i, &bh);
 517                 if (!ep) {
 518                         ret = -EIO;
 519                         goto release_fbh;
 520                 }
 521                 chksum = exfat_calc_chksum16(ep, DENTRY_SIZE, chksum,
 522                                 CS_DEFAULT);
 523                 brelse(bh);
 524         }
 525
 526         fep->dentry.file.checksum = cpu_to_le16(chksum);
 527         exfat_update_bh(fbh, IS_DIRSYNC(inode));
 528 release_fbh:
 529         brelse(fbh);
 530         return ret;
 531 }
 532
 533 static void exfat_free_benign_secondary_clusters(struct inode *inode,
 534                 struct exfat_dentry *ep)
 535 {
 536         struct super_block *sb = inode->i_sb;
 537         struct exfat_chain dir;
 538         unsigned int start_clu =
 539                 le32_to_cpu(ep->dentry.generic_secondary.start_clu);
 540         u64 size = le64_to_cpu(ep->dentry.generic_secondary.size);
 541         unsigned char flags = ep->dentry.generic_secondary.flags;
 542
 543         if (!(flags & ALLOC_POSSIBLE) || !start_clu || !size)
 544                 return;
 545
 546         exfat_chain_set(&dir, start_clu,
 547                         EXFAT_B_TO_CLU_ROUND_UP(size, EXFAT_SB(sb)),
 548                         flags);
 549         exfat_free_cluster(inode, &dir);
 550 }
 551
 552 int exfat_init_ext_entry(struct inode *inode, struct exfat_chain *p_dir,
 553                 int entry, int num_entries, struct exfat_uni_name *p_uniname)
 554 {
 555         struct super_block *sb = inode->i_sb;
 556         int i;
 557         unsigned short *uniname = p_uniname->name;
 558         struct exfat_dentry *ep;
 559         struct buffer_head *bh;
 560         int sync = IS_DIRSYNC(inode);
 561
 562         ep = exfat_get_dentry(sb, p_dir, entry, &bh);
 563         if (!ep)
 564                 return -EIO;
 565
 566         ep->dentry.file.num_ext = (unsigned char)(num_entries - 1);
 567         exfat_update_bh(bh, sync);
 568         brelse(bh);
 569
 570         ep = exfat_get_dentry(sb, p_dir, entry + 1, &bh);
 571         if (!ep)
 572                 return -EIO;
 573
 574         ep->dentry.stream.name_len = p_uniname->name_len;
 575         ep->dentry.stream.name_hash = cpu_to_le16(p_uniname->name_hash);
 576         exfat_update_bh(bh, sync);
 577         brelse(bh);
 578
 579         for (i = EXFAT_FIRST_CLUSTER; i < num_entries; i++) {
 580                 ep = exfat_get_dentry(sb, p_dir, entry + i, &bh);
 581                 if (!ep)
 582                         return -EIO;
 583
 584                 if (exfat_get_entry_type(ep) & TYPE_BENIGN_SEC)
 585                         exfat_free_benign_secondary_clusters(inode, ep);
 586
 587                 exfat_init_name_entry(ep, uniname);
 588                 exfat_update_bh(bh, sync);
 589                 brelse(bh);
 590                 uniname += EXFAT_FILE_NAME_LEN;
 591         }
 592
 593         exfat_update_dir_chksum(inode, p_dir, entry);
 594         return 0;
 595 }
 596
 597 int exfat_remove_entries(struct inode *inode, struct exfat_chain *p_dir,
 598                 int entry, int order, int num_entries)
 599 {
 600         struct super_block *sb = inode->i_sb;
 601         int i;
 602         struct exfat_dentry *ep;
 603         struct buffer_head *bh;
 604
 605         for (i = order; i < num_entries; i++) {
 606                 ep = exfat_get_dentry(sb, p_dir, entry + i, &bh);
 607                 if (!ep)
 608                         return -EIO;
 609
 610                 if (exfat_get_entry_type(ep) & TYPE_BENIGN_SEC)
 611                         exfat_free_benign_secondary_clusters(inode, ep);
 612
 613                 exfat_set_entry_type(ep, TYPE_DELETED);
 614                 exfat_update_bh(bh, IS_DIRSYNC(inode));
 615                 brelse(bh);
 616         }
 617
 618         return 0;
 619 }
 620
 621 void exfat_update_dir_chksum_with_entry_set(struct exfat_entry_set_cache *es)
 622 {
 623         int chksum_type = CS_DIR_ENTRY, i;
 624         unsigned short chksum = 0;
 625         struct exfat_dentry *ep;
 626
 627         for (i = ES_IDX_FILE; i < es->num_entries; i++) {
 628                 ep = exfat_get_dentry_cached(es, i);
 629                 chksum = exfat_calc_chksum16(ep, DENTRY_SIZE, chksum,
 630                                              chksum_type);
 631                 chksum_type = CS_DEFAULT;
 632         }
 633         ep = exfat_get_dentry_cached(es, ES_IDX_FILE);
 634         ep->dentry.file.checksum = cpu_to_le16(chksum);
 635         es->modified = true;
 636 }
 637
 638 int exfat_put_dentry_set(struct exfat_entry_set_cache *es, int sync)
 639 {
 640         int i, err = 0;
 641
 642         if (es->modified)
 643                 err = exfat_update_bhs(es->bh, es->num_bh, sync);
 644
 645         for (i = 0; i < es->num_bh; i++)
 646                 if (err)
 647                         bforget(es->bh[i]);
 648                 else
 649                         brelse(es->bh[i]);
 650
 651         if (IS_DYNAMIC_ES(es))
 652                 kfree(es->bh);
 653
 654         return err;
 655 }
 656
 657 static int exfat_walk_fat_chain(struct super_block *sb,
 658                 struct exfat_chain *p_dir, unsigned int byte_offset,
 659                 unsigned int *clu)
 660 {
 661         struct exfat_sb_info *sbi = EXFAT_SB(sb);
 662         unsigned int clu_offset;
 663         unsigned int cur_clu;
 664
 665         clu_offset = EXFAT_B_TO_CLU(byte_offset, sbi);
 666         cur_clu = p_dir->dir;
 667
 668         if (p_dir->flags == ALLOC_NO_FAT_CHAIN) {
 669                 cur_clu += clu_offset;
 670         } else {
 671                 while (clu_offset > 0) {
 672                         if (exfat_get_next_cluster(sb, &cur_clu))
 673                                 return -EIO;
 674                         if (cur_clu == EXFAT_EOF_CLUSTER) {
 675                                 exfat_fs_error(sb,
 676                                         "invalid dentry access beyond EOF (clu : %u, eidx : %d)",
 677                                         p_dir->dir,
 678                                         EXFAT_B_TO_DEN(byte_offset));
 679                                 return -EIO;
 680                         }
 681                         clu_offset--;
 682                 }
 683         }
 684
 685         *clu = cur_clu;
 686         return 0;
 687 }
 688
 689 static int exfat_find_location(struct super_block *sb, struct exfat_chain *p_dir,
 690                                int entry, sector_t *sector, int *offset)
 691 {
 692         int ret;
 693         unsigned int off, clu = 0;
 694         struct exfat_sb_info *sbi = EXFAT_SB(sb);
 695
 696         off = EXFAT_DEN_TO_B(entry);
 697
 698         ret = exfat_walk_fat_chain(sb, p_dir, off, &clu);
 699         if (ret)
 700                 return ret;
 701
 702         /* byte offset in cluster */
 703         off = EXFAT_CLU_OFFSET(off, sbi);
 704
 705         /* byte offset in sector    */
 706         *offset = EXFAT_BLK_OFFSET(off, sb);
 707
 708         /* sector offset in cluster */
 709         *sector = EXFAT_B_TO_BLK(off, sb);
 710         *sector += exfat_cluster_to_sector(sbi, clu);
 711         return 0;
 712 }
 713
 714 #define EXFAT_MAX_RA_SIZE     (128*1024)
 715 static int exfat_dir_readahead(struct super_block *sb, sector_t sec)
 716 {
 717         struct exfat_sb_info *sbi = EXFAT_SB(sb);
 718         struct buffer_head *bh;
 719         unsigned int max_ra_count = EXFAT_MAX_RA_SIZE >> sb->s_blocksize_bits;
 720         unsigned int page_ra_count = PAGE_SIZE >> sb->s_blocksize_bits;
 721         unsigned int adj_ra_count = max(sbi->sect_per_clus, page_ra_count);
 722         unsigned int ra_count = min(adj_ra_count, max_ra_count);
 723
 724         /* Read-ahead is not required */
 725         if (sbi->sect_per_clus == 1)
 726                 return 0;
 727
 728         if (sec < sbi->data_start_sector) {
 729                 exfat_err(sb, "requested sector is invalid(sect:%llu, root:%llu)",
 730                           (unsigned long long)sec, sbi->data_start_sector);
 731                 return -EIO;
 732         }
 733
 734         /* Not sector aligned with ra_count, resize ra_count to page size */
 735         if ((sec - sbi->data_start_sector) & (ra_count - 1))
 736                 ra_count = page_ra_count;
 737
 738         bh = sb_find_get_block(sb, sec);
 739         if (!bh || !buffer_uptodate(bh)) {
 740                 unsigned int i;
 741
 742                 for (i = 0; i < ra_count; i++)
 743                         sb_breadahead(sb, (sector_t)(sec + i));
 744         }
 745         brelse(bh);
 746         return 0;
 747 }
 748
 749 struct exfat_dentry *exfat_get_dentry(struct super_block *sb,
 750                 struct exfat_chain *p_dir, int entry, struct buffer_head **bh)
 751 {
 752         unsigned int dentries_per_page = EXFAT_B_TO_DEN(PAGE_SIZE);
 753         int off;
 754         sector_t sec;
 755
 756         if (p_dir->dir == DIR_DELETED) {
 757                 exfat_err(sb, "abnormal access to deleted dentry");
 758                 return NULL;
 759         }
 760
 761         if (exfat_find_location(sb, p_dir, entry, &sec, &off))
 762                 return NULL;
 763
 764         if (p_dir->dir != EXFAT_FREE_CLUSTER &&
 765                         !(entry & (dentries_per_page - 1)))
 766                 exfat_dir_readahead(sb, sec);
 767
 768         *bh = sb_bread(sb, sec);
 769         if (!*bh)
 770                 return NULL;
 771
 772         return (struct exfat_dentry *)((*bh)->b_data + off);
 773 }
 774
 775 enum exfat_validate_dentry_mode {
 776         ES_MODE_STARTED,
 777         ES_MODE_GET_FILE_ENTRY,
 778         ES_MODE_GET_STRM_ENTRY,
 779         ES_MODE_GET_NAME_ENTRY,
 780         ES_MODE_GET_CRITICAL_SEC_ENTRY,
 781         ES_MODE_GET_BENIGN_SEC_ENTRY,
 782 };
 783
 784 static bool exfat_validate_entry(unsigned int type,
 785                 enum exfat_validate_dentry_mode *mode)
 786 {
 787         if (type == TYPE_UNUSED || type == TYPE_DELETED)
 788                 return false;
 789
 790         switch (*mode) {
 791         case ES_MODE_STARTED:
 792                 if  (type != TYPE_FILE && type != TYPE_DIR)
 793                         return false;
 794                 *mode = ES_MODE_GET_FILE_ENTRY;
 795                 break;
 796         case ES_MODE_GET_FILE_ENTRY:
 797                 if (type != TYPE_STREAM)
 798                         return false;
 799                 *mode = ES_MODE_GET_STRM_ENTRY;
 800                 break;
 801         case ES_MODE_GET_STRM_ENTRY:
 802                 if (type != TYPE_EXTEND)
 803                         return false;
 804                 *mode = ES_MODE_GET_NAME_ENTRY;
 805                 break;
 806         case ES_MODE_GET_NAME_ENTRY:
 807                 if (type & TYPE_BENIGN_SEC)
 808                         *mode = ES_MODE_GET_BENIGN_SEC_ENTRY;
 809                 else if (type != TYPE_EXTEND)
 810                         return false;
 811                 break;
 812         case ES_MODE_GET_BENIGN_SEC_ENTRY:
 813                 /* Assume unreconized benign secondary entry */
 814                 if (!(type & TYPE_BENIGN_SEC))
 815                         return false;
 816                 break;
 817         default:
 818                 return false;
 819         }
 820
 821         return true;
 822 }
 823
 824 struct exfat_dentry *exfat_get_dentry_cached(
 825         struct exfat_entry_set_cache *es, int num)
 826 {
 827         int off = es->start_off + num * DENTRY_SIZE;
 828         struct buffer_head *bh = es->bh[EXFAT_B_TO_BLK(off, es->sb)];
 829         char *p = bh->b_data + EXFAT_BLK_OFFSET(off, es->sb);
 830
 831         return (struct exfat_dentry *)p;
 832 }
 833
 834 /*
 835  * Returns a set of dentries for a file or dir.
 836  *
 837  * Note It provides a direct pointer to bh->data via exfat_get_dentry_cached().
 838  * User should call exfat_get_dentry_set() after setting 'modified' to apply
 839  * changes made in this entry set to the real device.
 840  *
 841  * in:
 842  *   sb+p_dir+entry: indicates a file/dir
 843  *   type:  specifies how many dentries should be included.
 844  * return:
 845  *   pointer of entry set on success,
 846  *   NULL on failure.
 847  */
 848 int exfat_get_dentry_set(struct exfat_entry_set_cache *es,
 849                 struct super_block *sb, struct exfat_chain *p_dir, int entry,
 850                 unsigned int type)
 851 {
 852         int ret, i, num_bh;
 853         unsigned int off;
 854         sector_t sec;
 855         struct exfat_sb_info *sbi = EXFAT_SB(sb);
 856         struct exfat_dentry *ep;
 857         int num_entries;
 858         enum exfat_validate_dentry_mode mode = ES_MODE_STARTED;
 859         struct buffer_head *bh;
 860
 861         if (p_dir->dir == DIR_DELETED) {
 862                 exfat_err(sb, "access to deleted dentry");
 863                 return -EIO;
 864         }
 865
 866         ret = exfat_find_location(sb, p_dir, entry, &sec, &off);
 867         if (ret)
 868                 return ret;
 869
 870         memset(es, 0, sizeof(*es));
 871         es->sb = sb;
 872         es->modified = false;
 873         es->start_off = off;
 874         es->bh = es->__bh;
 875
 876         bh = sb_bread(sb, sec);
 877         if (!bh)
 878                 return -EIO;
 879         es->bh[es->num_bh++] = bh;
 880
 881         ep = exfat_get_dentry_cached(es, ES_IDX_FILE);
 882         if (!exfat_validate_entry(exfat_get_entry_type(ep), &mode))
 883                 goto put_es;
 884
 885         num_entries = type == ES_ALL_ENTRIES ?
 886                 ep->dentry.file.num_ext + 1 : type;
 887         es->num_entries = num_entries;
 888
 889         num_bh = EXFAT_B_TO_BLK_ROUND_UP(off + num_entries * DENTRY_SIZE, sb);
 890         if (num_bh > ARRAY_SIZE(es->__bh)) {
 891                 es->bh = kmalloc_array(num_bh, sizeof(*es->bh), GFP_KERNEL);
 892                 if (!es->bh) {
 893                         brelse(bh);
 894                         return -ENOMEM;
 895                 }
 896                 es->bh[0] = bh;
 897         }
 898
 899         for (i = 1; i < num_bh; i++) {
 900                 /* get the next sector */
 901                 if (exfat_is_last_sector_in_cluster(sbi, sec)) {
 902                         unsigned int clu = exfat_sector_to_cluster(sbi, sec);
 903
 904                         if (p_dir->flags == ALLOC_NO_FAT_CHAIN)
 905                                 clu++;
 906                         else if (exfat_get_next_cluster(sb, &clu))
 907                                 goto put_es;
 908                         sec = exfat_cluster_to_sector(sbi, clu);
 909                 } else {
 910                         sec++;
 911                 }
 912
 913                 bh = sb_bread(sb, sec);
 914                 if (!bh)
 915                         goto put_es;
 916                 es->bh[es->num_bh++] = bh;
 917         }
 918
 919         /* validate cached dentries */
 920         for (i = ES_IDX_STREAM; i < num_entries; i++) {
 921                 ep = exfat_get_dentry_cached(es, i);
 922                 if (!exfat_validate_entry(exfat_get_entry_type(ep), &mode))
 923                         goto put_es;
 924         }
 925         return 0;
 926
 927 put_es:
 928         exfat_put_dentry_set(es, false);
 929         return -EIO;
 930 }
 931
 932 static inline void exfat_reset_empty_hint(struct exfat_hint_femp *hint_femp)
 933 {
 934         hint_femp->eidx = EXFAT_HINT_NONE;
 935         hint_femp->count = 0;
 936 }
 937
 938 static inline void exfat_set_empty_hint(struct exfat_inode_info *ei,
 939                 struct exfat_hint_femp *candi_empty, struct exfat_chain *clu,
 940                 int dentry, int num_entries, int entry_type)
 941 {
 942         if (ei->hint_femp.eidx == EXFAT_HINT_NONE ||
 943             ei->hint_femp.eidx > dentry) {
 944                 int total_entries = EXFAT_B_TO_DEN(i_size_read(&ei->vfs_inode));
 945
 946                 if (candi_empty->count == 0) {
 947                         candi_empty->cur = *clu;
 948                         candi_empty->eidx = dentry;
 949                 }
 950
 951                 if (entry_type == TYPE_UNUSED)
 952                         candi_empty->count += total_entries - dentry;
 953                 else
 954                         candi_empty->count++;
 955
 956                 if (candi_empty->count == num_entries ||
 957                     candi_empty->count + candi_empty->eidx == total_entries)
 958                         ei->hint_femp = *candi_empty;
 959         }
 960 }
 961
 962 enum {
 963         DIRENT_STEP_FILE,
 964         DIRENT_STEP_STRM,
 965         DIRENT_STEP_NAME,
 966         DIRENT_STEP_SECD,
 967 };
 968
 969 /*
 970  * @ei:         inode info of parent directory
 971  * @p_dir:      directory structure of parent directory
 972  * @num_entries:entry size of p_uniname
 973  * @hint_opt:   If p_uniname is found, filled with optimized dir/entry
 974  *              for traversing cluster chain.
 975  * @return:
 976  *   >= 0:      file directory entry position where the name exists
 977  *   -ENOENT:   entry with the name does not exist
 978  *   -EIO:      I/O error
 979  */
 980 int exfat_find_dir_entry(struct super_block *sb, struct exfat_inode_info *ei,
 981                 struct exfat_chain *p_dir, struct exfat_uni_name *p_uniname,
 982                 struct exfat_hint *hint_opt)
 983 {
 984         int i, rewind = 0, dentry = 0, end_eidx = 0, num_ext = 0, len;
 985         int order, step, name_len = 0;
 986         int dentries_per_clu;
 987         unsigned int entry_type;
 988         unsigned short *uniname = NULL;
 989         struct exfat_chain clu;
 990         struct exfat_hint *hint_stat = &ei->hint_stat;
 991         struct exfat_hint_femp candi_empty;
 992         struct exfat_sb_info *sbi = EXFAT_SB(sb);
 993         int num_entries = exfat_calc_num_entries(p_uniname);
 994
 995         if (num_entries < 0)
 996                 return num_entries;
 997
 998         dentries_per_clu = sbi->dentries_per_clu;
 999
1000         exfat_chain_dup(&clu, p_dir);
1001
1002         if (hint_stat->eidx) {
1003                 clu.dir = hint_stat->clu;
1004                 dentry = hint_stat->eidx;
1005                 end_eidx = dentry;
1006         }
1007
1008         exfat_reset_empty_hint(&ei->hint_femp);
1009
1010 rewind:
1011         order = 0;
1012         step = DIRENT_STEP_FILE;
1013         exfat_reset_empty_hint(&candi_empty);
1014
1015         while (clu.dir != EXFAT_EOF_CLUSTER) {
1016                 i = dentry & (dentries_per_clu - 1);
1017                 for (; i < dentries_per_clu; i++, dentry++) {
1018                         struct exfat_dentry *ep;
1019                         struct buffer_head *bh;
1020
1021                         if (rewind && dentry == end_eidx)
1022                                 goto not_found;
1023
1024                         ep = exfat_get_dentry(sb, &clu, i, &bh);
1025                         if (!ep)
1026                                 return -EIO;
1027
1028                         entry_type = exfat_get_entry_type(ep);
1029
1030                         if (entry_type == TYPE_UNUSED ||
1031                             entry_type == TYPE_DELETED) {
1032                                 step = DIRENT_STEP_FILE;
1033
1034                                 exfat_set_empty_hint(ei, &candi_empty, &clu,
1035                                                 dentry, num_entries,
1036                                                 entry_type);
1037
1038                                 brelse(bh);
1039                                 if (entry_type == TYPE_UNUSED)
1040                                         goto not_found;
1041                                 continue;
1042                         }
1043
1044                         exfat_reset_empty_hint(&candi_empty);
1045
1046                         if (entry_type == TYPE_FILE || entry_type == TYPE_DIR) {
1047                                 step = DIRENT_STEP_FILE;
1048                                 hint_opt->clu = clu.dir;
1049                                 hint_opt->eidx = i;
1050                                 num_ext = ep->dentry.file.num_ext;
1051                                 step = DIRENT_STEP_STRM;
1052                                 brelse(bh);
1053                                 continue;
1054                         }
1055
1056                         if (entry_type == TYPE_STREAM) {
1057                                 u16 name_hash;
1058
1059                                 if (step != DIRENT_STEP_STRM) {
1060                                         step = DIRENT_STEP_FILE;
1061                                         brelse(bh);
1062                                         continue;
1063                                 }
1064                                 step = DIRENT_STEP_FILE;
1065                                 name_hash = le16_to_cpu(
1066                                                 ep->dentry.stream.name_hash);
1067                                 if (p_uniname->name_hash == name_hash &&
1068                                     p_uniname->name_len ==
1069                                                 ep->dentry.stream.name_len) {
1070                                         step = DIRENT_STEP_NAME;
1071                                         order = 1;
1072                                         name_len = 0;
1073                                 }
1074                                 brelse(bh);
1075                                 continue;
1076                         }
1077
1078                         brelse(bh);
1079                         if (entry_type == TYPE_EXTEND) {
1080                                 unsigned short entry_uniname[16], unichar;
1081
1082                                 if (step != DIRENT_STEP_NAME) {
1083                                         step = DIRENT_STEP_FILE;
1084                                         continue;
1085                                 }
1086
1087                                 if (++order == 2)
1088                                         uniname = p_uniname->name;
1089                                 else
1090                                         uniname += EXFAT_FILE_NAME_LEN;
1091
1092                                 len = exfat_extract_uni_name(ep, entry_uniname);
1093                                 name_len += len;
1094
1095                                 unichar = *(uniname+len);
1096                                 *(uniname+len) = 0x0;
1097
1098                                 if (exfat_uniname_ncmp(sb, uniname,
1099                                         entry_uniname, len)) {
1100                                         step = DIRENT_STEP_FILE;
1101                                 } else if (p_uniname->name_len == name_len) {
1102                                         if (order == num_ext)
1103                                                 goto found;
1104                                         step = DIRENT_STEP_SECD;
1105                                 }
1106
1107                                 *(uniname+len) = unichar;
1108                                 continue;
1109                         }
1110
1111                         if (entry_type &
1112                                         (TYPE_CRITICAL_SEC | TYPE_BENIGN_SEC)) {
1113                                 if (step == DIRENT_STEP_SECD) {
1114                                         if (++order == num_ext)
1115                                                 goto found;
1116                                         continue;
1117                                 }
1118                         }
1119                         step = DIRENT_STEP_FILE;
1120                 }
1121
1122                 if (clu.flags == ALLOC_NO_FAT_CHAIN) {
1123                         if (--clu.size > 0)
1124                                 clu.dir++;
1125                         else
1126                                 clu.dir = EXFAT_EOF_CLUSTER;
1127                 } else {
1128                         if (exfat_get_next_cluster(sb, &clu.dir))
1129                                 return -EIO;
1130                 }
1131         }
1132
1133 not_found:
1134         /*
1135          * We started at not 0 index,so we should try to find target
1136          * from 0 index to the index we started at.
1137          */
1138         if (!rewind && end_eidx) {
1139                 rewind = 1;
1140                 dentry = 0;
1141                 clu.dir = p_dir->dir;
1142                 goto rewind;
1143         }
1144
1145         /*
1146          * set the EXFAT_EOF_CLUSTER flag to avoid search
1147          * from the beginning again when allocated a new cluster
1148          */
1149         if (ei->hint_femp.eidx == EXFAT_HINT_NONE) {
1150                 ei->hint_femp.cur.dir = EXFAT_EOF_CLUSTER;
1151                 ei->hint_femp.eidx = p_dir->size * dentries_per_clu;
1152                 ei->hint_femp.count = 0;
1153         }
1154
1155         /* initialized hint_stat */
1156         hint_stat->clu = p_dir->dir;
1157         hint_stat->eidx = 0;
1158         return -ENOENT;
1159
1160 found:
1161         /* next dentry we'll find is out of this cluster */
1162         if (!((dentry + 1) & (dentries_per_clu - 1))) {
1163                 int ret = 0;
1164
1165                 if (clu.flags == ALLOC_NO_FAT_CHAIN) {
1166                         if (--clu.size > 0)
1167                                 clu.dir++;
1168                         else
1169                                 clu.dir = EXFAT_EOF_CLUSTER;
1170                 } else {
1171                         ret = exfat_get_next_cluster(sb, &clu.dir);
1172                 }
1173
1174                 if (ret || clu.dir == EXFAT_EOF_CLUSTER) {
1175                         /* just initialized hint_stat */
1176                         hint_stat->clu = p_dir->dir;
1177                         hint_stat->eidx = 0;
1178                         return (dentry - num_ext);
1179                 }
1180         }
1181
1182         hint_stat->clu = clu.dir;
1183         hint_stat->eidx = dentry + 1;
1184         return dentry - num_ext;
1185 }
1186
1187 int exfat_count_ext_entries(struct super_block *sb, struct exfat_chain *p_dir,
1188                 int entry, struct exfat_dentry *ep)
1189 {
1190         int i, count = 0;
1191         unsigned int type;
1192         struct exfat_dentry *ext_ep;
1193         struct buffer_head *bh;
1194
1195         for (i = 0, entry++; i < ep->dentry.file.num_ext; i++, entry++) {
1196                 ext_ep = exfat_get_dentry(sb, p_dir, entry, &bh);
1197                 if (!ext_ep)
1198                         return -EIO;
1199
1200                 type = exfat_get_entry_type(ext_ep);
1201                 brelse(bh);
1202                 if (type & TYPE_CRITICAL_SEC || type & TYPE_BENIGN_SEC)
1203                         count++;
1204         }
1205         return count;
1206 }
1207
1208 int exfat_count_dir_entries(struct super_block *sb, struct exfat_chain *p_dir)
1209 {
1210         int i, count = 0;
1211         int dentries_per_clu;
1212         unsigned int entry_type;
1213         struct exfat_chain clu;
1214         struct exfat_dentry *ep;
1215         struct exfat_sb_info *sbi = EXFAT_SB(sb);
1216         struct buffer_head *bh;
1217
1218         dentries_per_clu = sbi->dentries_per_clu;
1219
1220         exfat_chain_dup(&clu, p_dir);
1221
1222         while (clu.dir != EXFAT_EOF_CLUSTER) {
1223                 for (i = 0; i < dentries_per_clu; i++) {
1224                         ep = exfat_get_dentry(sb, &clu, i, &bh);
1225                         if (!ep)
1226                                 return -EIO;
1227                         entry_type = exfat_get_entry_type(ep);
1228                         brelse(bh);
1229
1230                         if (entry_type == TYPE_UNUSED)
1231                                 return count;
1232                         if (entry_type != TYPE_DIR)
1233                                 continue;
1234                         count++;
1235                 }
1236
1237                 if (clu.flags == ALLOC_NO_FAT_CHAIN) {
1238                         if (--clu.size > 0)
1239                                 clu.dir++;
1240                         else
1241                                 clu.dir = EXFAT_EOF_CLUSTER;
1242                 } else {
1243                         if (exfat_get_next_cluster(sb, &(clu.dir)))
1244                                 return -EIO;
1245                 }
1246         }
1247
1248         return count;
1249 }