fs/hfsplus/dir.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  *  linux/fs/hfsplus/dir.c
   4  *
   5  * Copyright (C) 2001
   6  * Brad Boyer (flar@allandria.com)
   7  * (C) 2003 Ardis Technologies <roman@ardistech.com>
   8  *
   9  * Handling of directories
  10  */
  11
  12 #include <linux/errno.h>
  13 #include <linux/fs.h>
  14 #include <linux/slab.h>
  15 #include <linux/random.h>
  16 #include <linux/nls.h>
  17
  18 #include "hfsplus_fs.h"
  19 #include "hfsplus_raw.h"
  20 #include "xattr.h"
  21 #include "acl.h"
  22
  23 static inline void hfsplus_instantiate(struct dentry *dentry,
  24                                        struct inode *inode, u32 cnid)
  25 {
  26         dentry->d_fsdata = (void *)(unsigned long)cnid;
  27         d_instantiate(dentry, inode);
  28 }
  29
  30 /* Find the entry inside dir named dentry->d_name */
  31 static struct dentry *hfsplus_lookup(struct inode *dir, struct dentry *dentry,
  32                                      unsigned int flags)
  33 {
  34         struct inode *inode = NULL;
  35         struct hfs_find_data fd;
  36         struct super_block *sb;
  37         hfsplus_cat_entry entry;
  38         int err;
  39         u32 cnid, linkid = 0;
  40         u16 type;
  41
  42         sb = dir->i_sb;
  43
  44         dentry->d_fsdata = NULL;
  45         err = hfs_find_init(HFSPLUS_SB(sb)->cat_tree, &fd);
  46         if (err)
  47                 return ERR_PTR(err);
  48         err = hfsplus_cat_build_key(sb, fd.search_key, dir->i_ino,
  49                         &dentry->d_name);
  50         if (unlikely(err < 0))
  51                 goto fail;
  52 again:
  53         err = hfs_brec_read(&fd, &entry, sizeof(entry));
  54         if (err) {
  55                 if (err == -ENOENT) {
  56                         hfs_find_exit(&fd);
  57                         /* No such entry */
  58                         inode = NULL;
  59                         goto out;
  60                 }
  61                 goto fail;
  62         }
  63         type = be16_to_cpu(entry.type);
  64         if (type == HFSPLUS_FOLDER) {
  65                 if (fd.entrylength < sizeof(struct hfsplus_cat_folder)) {
  66                         err = -EIO;
  67                         goto fail;
  68                 }
  69                 cnid = be32_to_cpu(entry.folder.id);
  70                 dentry->d_fsdata = (void *)(unsigned long)cnid;
  71         } else if (type == HFSPLUS_FILE) {
  72                 if (fd.entrylength < sizeof(struct hfsplus_cat_file)) {
  73                         err = -EIO;
  74                         goto fail;
  75                 }
  76                 cnid = be32_to_cpu(entry.file.id);
  77                 if (entry.file.user_info.fdType ==
  78                                 cpu_to_be32(HFSP_HARDLINK_TYPE) &&
  79                                 entry.file.user_info.fdCreator ==
  80                                 cpu_to_be32(HFSP_HFSPLUS_CREATOR) &&
  81                                 (entry.file.create_date ==
  82                                         HFSPLUS_I(HFSPLUS_SB(sb)->hidden_dir)->
  83                                                 create_date ||
  84                                 entry.file.create_date ==
  85                                         HFSPLUS_I(d_inode(sb->s_root))->
  86                                                 create_date) &&
  87                                 HFSPLUS_SB(sb)->hidden_dir) {
  88                         struct qstr str;
  89                         char name[32];
  90
  91                         if (dentry->d_fsdata) {
  92                                 /*
  93                                  * We found a link pointing to another link,
  94                                  * so ignore it and treat it as regular file.
  95                                  */
  96                                 cnid = (unsigned long)dentry->d_fsdata;
  97                                 linkid = 0;
  98                         } else {
  99                                 dentry->d_fsdata = (void *)(unsigned long)cnid;
 100                                 linkid =
 101                                         be32_to_cpu(entry.file.permissions.dev);
 102                                 str.len = sprintf(name, "iNode%d", linkid);
 103                                 str.name = name;
 104                                 err = hfsplus_cat_build_key(sb, fd.search_key,
 105                                         HFSPLUS_SB(sb)->hidden_dir->i_ino,
 106                                         &str);
 107                                 if (unlikely(err < 0))
 108                                         goto fail;
 109                                 goto again;
 110                         }
 111                 } else if (!dentry->d_fsdata)
 112                         dentry->d_fsdata = (void *)(unsigned long)cnid;
 113         } else {
 114                 pr_err("invalid catalog entry type in lookup\n");
 115                 err = -EIO;
 116                 goto fail;
 117         }
 118         hfs_find_exit(&fd);
 119         inode = hfsplus_iget(dir->i_sb, cnid);
 120         if (IS_ERR(inode))
 121                 return ERR_CAST(inode);
 122         if (S_ISREG(inode->i_mode))
 123                 HFSPLUS_I(inode)->linkid = linkid;
 124 out:
 125         d_add(dentry, inode);
 126         return NULL;
 127 fail:
 128         hfs_find_exit(&fd);
 129         return ERR_PTR(err);
 130 }
 131
 132 static int hfsplus_readdir(struct file *file, struct dir_context *ctx)
 133 {
 134         struct inode *inode = file_inode(file);
 135         struct super_block *sb = inode->i_sb;
 136         int len, err;
 137         char *strbuf;
 138         hfsplus_cat_entry entry;
 139         struct hfs_find_data fd;
 140         struct hfsplus_readdir_data *rd;
 141         u16 type;
 142
 143         if (file->f_pos >= inode->i_size)
 144                 return 0;
 145
 146         err = hfs_find_init(HFSPLUS_SB(sb)->cat_tree, &fd);
 147         if (err)
 148                 return err;
 149         strbuf = kmalloc(NLS_MAX_CHARSET_SIZE * HFSPLUS_MAX_STRLEN + 1, GFP_KERNEL);
 150         if (!strbuf) {
 151                 err = -ENOMEM;
 152                 goto out;
 153         }
 154         hfsplus_cat_build_key_with_cnid(sb, fd.search_key, inode->i_ino);
 155         err = hfs_brec_find(&fd, hfs_find_rec_by_key);
 156         if (err)
 157                 goto out;
 158
 159         if (ctx->pos == 0) {
 160                 /* This is completely artificial... */
 161                 if (!dir_emit_dot(file, ctx))
 162                         goto out;
 163                 ctx->pos = 1;
 164         }
 165         if (ctx->pos == 1) {
 166                 if (fd.entrylength > sizeof(entry) || fd.entrylength < 0) {
 167                         err = -EIO;
 168                         goto out;
 169                 }
 170
 171                 hfs_bnode_read(fd.bnode, &entry, fd.entryoffset,
 172                         fd.entrylength);
 173                 if (be16_to_cpu(entry.type) != HFSPLUS_FOLDER_THREAD) {
 174                         pr_err("bad catalog folder thread\n");
 175                         err = -EIO;
 176                         goto out;
 177                 }
 178                 if (fd.entrylength < HFSPLUS_MIN_THREAD_SZ) {
 179                         pr_err("truncated catalog thread\n");
 180                         err = -EIO;
 181                         goto out;
 182                 }
 183                 if (!dir_emit(ctx, "..", 2,
 184                             be32_to_cpu(entry.thread.parentID), DT_DIR))
 185                         goto out;
 186                 ctx->pos = 2;
 187         }
 188         if (ctx->pos >= inode->i_size)
 189                 goto out;
 190         err = hfs_brec_goto(&fd, ctx->pos - 1);
 191         if (err)
 192                 goto out;
 193         for (;;) {
 194                 if (be32_to_cpu(fd.key->cat.parent) != inode->i_ino) {
 195                         pr_err("walked past end of dir\n");
 196                         err = -EIO;
 197                         goto out;
 198                 }
 199
 200                 if (fd.entrylength > sizeof(entry) || fd.entrylength < 0) {
 201                         err = -EIO;
 202                         goto out;
 203                 }
 204
 205                 hfs_bnode_read(fd.bnode, &entry, fd.entryoffset,
 206                         fd.entrylength);
 207                 type = be16_to_cpu(entry.type);
 208                 len = NLS_MAX_CHARSET_SIZE * HFSPLUS_MAX_STRLEN;
 209                 err = hfsplus_uni2asc(sb, &fd.key->cat.name, strbuf, &len);
 210                 if (err)
 211                         goto out;
 212                 if (type == HFSPLUS_FOLDER) {
 213                         if (fd.entrylength <
 214                                         sizeof(struct hfsplus_cat_folder)) {
 215                                 pr_err("small dir entry\n");
 216                                 err = -EIO;
 217                                 goto out;
 218                         }
 219                         if (HFSPLUS_SB(sb)->hidden_dir &&
 220                             HFSPLUS_SB(sb)->hidden_dir->i_ino ==
 221                                         be32_to_cpu(entry.folder.id))
 222                                 goto next;
 223                         if (!dir_emit(ctx, strbuf, len,
 224                                     be32_to_cpu(entry.folder.id), DT_DIR))
 225                                 break;
 226                 } else if (type == HFSPLUS_FILE) {
 227                         u16 mode;
 228                         unsigned type = DT_UNKNOWN;
 229
 230                         if (fd.entrylength < sizeof(struct hfsplus_cat_file)) {
 231                                 pr_err("small file entry\n");
 232                                 err = -EIO;
 233                                 goto out;
 234                         }
 235
 236                         mode = be16_to_cpu(entry.file.permissions.mode);
 237                         if (S_ISREG(mode))
 238                                 type = DT_REG;
 239                         else if (S_ISLNK(mode))
 240                                 type = DT_LNK;
 241                         else if (S_ISFIFO(mode))
 242                                 type = DT_FIFO;
 243                         else if (S_ISCHR(mode))
 244                                 type = DT_CHR;
 245                         else if (S_ISBLK(mode))
 246                                 type = DT_BLK;
 247                         else if (S_ISSOCK(mode))
 248                                 type = DT_SOCK;
 249
 250                         if (!dir_emit(ctx, strbuf, len,
 251                                       be32_to_cpu(entry.file.id), type))
 252                                 break;
 253                 } else {
 254                         pr_err("bad catalog entry type\n");
 255                         err = -EIO;
 256                         goto out;
 257                 }
 258 next:
 259                 ctx->pos++;
 260                 if (ctx->pos >= inode->i_size)
 261                         goto out;
 262                 err = hfs_brec_goto(&fd, 1);
 263                 if (err)
 264                         goto out;
 265         }
 266         rd = file->private_data;
 267         if (!rd) {
 268                 rd = kmalloc(sizeof(struct hfsplus_readdir_data), GFP_KERNEL);
 269                 if (!rd) {
 270                         err = -ENOMEM;
 271                         goto out;
 272                 }
 273                 file->private_data = rd;
 274                 rd->file = file;
 275                 spin_lock(&HFSPLUS_I(inode)->open_dir_lock);
 276                 list_add(&rd->list, &HFSPLUS_I(inode)->open_dir_list);
 277                 spin_unlock(&HFSPLUS_I(inode)->open_dir_lock);
 278         }
 279         /*
 280          * Can be done after the list insertion; exclusion with
 281          * hfsplus_delete_cat() is provided by directory lock.
 282          */
 283         memcpy(&rd->key, fd.key, sizeof(struct hfsplus_cat_key));
 284 out:
 285         kfree(strbuf);
 286         hfs_find_exit(&fd);
 287         return err;
 288 }
 289
 290 static int hfsplus_dir_release(struct inode *inode, struct file *file)
 291 {
 292         struct hfsplus_readdir_data *rd = file->private_data;
 293         if (rd) {
 294                 spin_lock(&HFSPLUS_I(inode)->open_dir_lock);
 295                 list_del(&rd->list);
 296                 spin_unlock(&HFSPLUS_I(inode)->open_dir_lock);
 297                 kfree(rd);
 298         }
 299         return 0;
 300 }
 301
 302 static int hfsplus_link(struct dentry *src_dentry, struct inode *dst_dir,
 303                         struct dentry *dst_dentry)
 304 {
 305         struct hfsplus_sb_info *sbi = HFSPLUS_SB(dst_dir->i_sb);
 306         struct inode *inode = d_inode(src_dentry);
 307         struct inode *src_dir = d_inode(src_dentry->d_parent);
 308         struct qstr str;
 309         char name[32];
 310         u32 cnid, id;
 311         int res;
 312
 313         if (HFSPLUS_IS_RSRC(inode))
 314                 return -EPERM;
 315         if (!S_ISREG(inode->i_mode))
 316                 return -EPERM;
 317
 318         mutex_lock(&sbi->vh_mutex);
 319         if (inode->i_ino == (u32)(unsigned long)src_dentry->d_fsdata) {
 320                 for (;;) {
 321                         get_random_bytes(&id, sizeof(cnid));
 322                         id &= 0x3fffffff;
 323                         str.name = name;
 324                         str.len = sprintf(name, "iNode%d", id);
 325                         res = hfsplus_rename_cat(inode->i_ino,
 326                                                  src_dir, &src_dentry->d_name,
 327                                                  sbi->hidden_dir, &str);
 328                         if (!res)
 329                                 break;
 330                         if (res != -EEXIST)
 331                                 goto out;
 332                 }
 333                 HFSPLUS_I(inode)->linkid = id;
 334                 cnid = sbi->next_cnid++;
 335                 src_dentry->d_fsdata = (void *)(unsigned long)cnid;
 336                 res = hfsplus_create_cat(cnid, src_dir,
 337                         &src_dentry->d_name, inode);
 338                 if (res)
 339                         /* panic? */
 340                         goto out;
 341                 sbi->file_count++;
 342         }
 343         cnid = sbi->next_cnid++;
 344         res = hfsplus_create_cat(cnid, dst_dir, &dst_dentry->d_name, inode);
 345         if (res)
 346                 goto out;
 347
 348         inc_nlink(inode);
 349         hfsplus_instantiate(dst_dentry, inode, cnid);
 350         ihold(inode);
 351         inode->i_ctime = current_time(inode);
 352         mark_inode_dirty(inode);
 353         sbi->file_count++;
 354         hfsplus_mark_mdb_dirty(dst_dir->i_sb);
 355 out:
 356         mutex_unlock(&sbi->vh_mutex);
 357         return res;
 358 }
 359
 360 static int hfsplus_unlink(struct inode *dir, struct dentry *dentry)
 361 {
 362         struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
 363         struct inode *inode = d_inode(dentry);
 364         struct qstr str;
 365         char name[32];
 366         u32 cnid;
 367         int res;
 368
 369         if (HFSPLUS_IS_RSRC(inode))
 370                 return -EPERM;
 371
 372         mutex_lock(&sbi->vh_mutex);
 373         cnid = (u32)(unsigned long)dentry->d_fsdata;
 374         if (inode->i_ino == cnid &&
 375             atomic_read(&HFSPLUS_I(inode)->opencnt)) {
 376                 str.name = name;
 377                 str.len = sprintf(name, "temp%lu", inode->i_ino);
 378                 res = hfsplus_rename_cat(inode->i_ino,
 379                                          dir, &dentry->d_name,
 380                                          sbi->hidden_dir, &str);
 381                 if (!res) {
 382                         inode->i_flags |= S_DEAD;
 383                         drop_nlink(inode);
 384                 }
 385                 goto out;
 386         }
 387         res = hfsplus_delete_cat(cnid, dir, &dentry->d_name);
 388         if (res)
 389                 goto out;
 390
 391         if (inode->i_nlink > 0)
 392                 drop_nlink(inode);
 393         if (inode->i_ino == cnid)
 394                 clear_nlink(inode);
 395         if (!inode->i_nlink) {
 396                 if (inode->i_ino != cnid) {
 397                         sbi->file_count--;
 398                         if (!atomic_read(&HFSPLUS_I(inode)->opencnt)) {
 399                                 res = hfsplus_delete_cat(inode->i_ino,
 400                                                          sbi->hidden_dir,
 401                                                          NULL);
 402                                 if (!res)
 403                                         hfsplus_delete_inode(inode);
 404                         } else
 405                                 inode->i_flags |= S_DEAD;
 406                 } else
 407                         hfsplus_delete_inode(inode);
 408         } else
 409                 sbi->file_count--;
 410         inode->i_ctime = current_time(inode);
 411         mark_inode_dirty(inode);
 412 out:
 413         mutex_unlock(&sbi->vh_mutex);
 414         return res;
 415 }
 416
 417 static int hfsplus_rmdir(struct inode *dir, struct dentry *dentry)
 418 {
 419         struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
 420         struct inode *inode = d_inode(dentry);
 421         int res;
 422
 423         if (inode->i_size != 2)
 424                 return -ENOTEMPTY;
 425
 426         mutex_lock(&sbi->vh_mutex);
 427         res = hfsplus_delete_cat(inode->i_ino, dir, &dentry->d_name);
 428         if (res)
 429                 goto out;
 430         clear_nlink(inode);
 431         inode->i_ctime = current_time(inode);
 432         hfsplus_delete_inode(inode);
 433         mark_inode_dirty(inode);
 434 out:
 435         mutex_unlock(&sbi->vh_mutex);
 436         return res;
 437 }
 438
 439 static int hfsplus_symlink(struct inode *dir, struct dentry *dentry,
 440                            const char *symname)
 441 {
 442         struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
 443         struct inode *inode;
 444         int res = -ENOMEM;
 445
 446         mutex_lock(&sbi->vh_mutex);
 447         inode = hfsplus_new_inode(dir->i_sb, dir, S_IFLNK | S_IRWXUGO);
 448         if (!inode)
 449                 goto out;
 450
 451         res = page_symlink(inode, symname, strlen(symname) + 1);
 452         if (res)
 453                 goto out_err;
 454
 455         res = hfsplus_create_cat(inode->i_ino, dir, &dentry->d_name, inode);
 456         if (res)
 457                 goto out_err;
 458
 459         res = hfsplus_init_inode_security(inode, dir, &dentry->d_name);
 460         if (res == -EOPNOTSUPP)
 461                 res = 0; /* Operation is not supported. */
 462         else if (res) {
 463                 /* Try to delete anyway without error analysis. */
 464                 hfsplus_delete_cat(inode->i_ino, dir, &dentry->d_name);
 465                 goto out_err;
 466         }
 467
 468         hfsplus_instantiate(dentry, inode, inode->i_ino);
 469         mark_inode_dirty(inode);
 470         goto out;
 471
 472 out_err:
 473         clear_nlink(inode);
 474         hfsplus_delete_inode(inode);
 475         iput(inode);
 476 out:
 477         mutex_unlock(&sbi->vh_mutex);
 478         return res;
 479 }
 480
 481 static int hfsplus_mknod(struct inode *dir, struct dentry *dentry,
 482                          umode_t mode, dev_t rdev)
 483 {
 484         struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
 485         struct inode *inode;
 486         int res = -ENOMEM;
 487
 488         mutex_lock(&sbi->vh_mutex);
 489         inode = hfsplus_new_inode(dir->i_sb, dir, mode);
 490         if (!inode)
 491                 goto out;
 492
 493         if (S_ISBLK(mode) || S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode))
 494                 init_special_inode(inode, mode, rdev);
 495
 496         res = hfsplus_create_cat(inode->i_ino, dir, &dentry->d_name, inode);
 497         if (res)
 498                 goto failed_mknod;
 499
 500         res = hfsplus_init_inode_security(inode, dir, &dentry->d_name);
 501         if (res == -EOPNOTSUPP)
 502                 res = 0; /* Operation is not supported. */
 503         else if (res) {
 504                 /* Try to delete anyway without error analysis. */
 505                 hfsplus_delete_cat(inode->i_ino, dir, &dentry->d_name);
 506                 goto failed_mknod;
 507         }
 508
 509         hfsplus_instantiate(dentry, inode, inode->i_ino);
 510         mark_inode_dirty(inode);
 511         goto out;
 512
 513 failed_mknod:
 514         clear_nlink(inode);
 515         hfsplus_delete_inode(inode);
 516         iput(inode);
 517 out:
 518         mutex_unlock(&sbi->vh_mutex);
 519         return res;
 520 }
 521
 522 static int hfsplus_create(struct inode *dir, struct dentry *dentry, umode_t mode,
 523                           bool excl)
 524 {
 525         return hfsplus_mknod(dir, dentry, mode, 0);
 526 }
 527
 528 static int hfsplus_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
 529 {
 530         return hfsplus_mknod(dir, dentry, mode | S_IFDIR, 0);
 531 }
 532
 533 static int hfsplus_rename(struct inode *old_dir, struct dentry *old_dentry,
 534                           struct inode *new_dir, struct dentry *new_dentry,
 535                           unsigned int flags)
 536 {
 537         int res;
 538
 539         if (flags & ~RENAME_NOREPLACE)
 540                 return -EINVAL;
 541
 542         /* Unlink destination if it already exists */
 543         if (d_really_is_positive(new_dentry)) {
 544                 if (d_is_dir(new_dentry))
 545                         res = hfsplus_rmdir(new_dir, new_dentry);
 546                 else
 547                         res = hfsplus_unlink(new_dir, new_dentry);
 548                 if (res)
 549                         return res;
 550         }
 551
 552         res = hfsplus_rename_cat((u32)(unsigned long)old_dentry->d_fsdata,
 553                                  old_dir, &old_dentry->d_name,
 554                                  new_dir, &new_dentry->d_name);
 555         if (!res)
 556                 new_dentry->d_fsdata = old_dentry->d_fsdata;
 557         return res;
 558 }
 559
 560 const struct inode_operations hfsplus_dir_inode_operations = {
 561         .lookup                 = hfsplus_lookup,
 562         .create                 = hfsplus_create,
 563         .link                   = hfsplus_link,
 564         .unlink                 = hfsplus_unlink,
 565         .mkdir                  = hfsplus_mkdir,
 566         .rmdir                  = hfsplus_rmdir,
 567         .symlink                = hfsplus_symlink,
 568         .mknod                  = hfsplus_mknod,
 569         .rename                 = hfsplus_rename,
 570         .listxattr              = hfsplus_listxattr,
 571 #ifdef CONFIG_HFSPLUS_FS_POSIX_ACL
 572         .get_acl                = hfsplus_get_posix_acl,
 573         .set_acl                = hfsplus_set_posix_acl,
 574 #endif
 575 };
 576
 577 const struct file_operations hfsplus_dir_operations = {
 578         .fsync          = hfsplus_file_fsync,
 579         .read           = generic_read_dir,
 580         .iterate_shared = hfsplus_readdir,
 581         .unlocked_ioctl = hfsplus_ioctl,
 582         .llseek         = generic_file_llseek,
 583         .release        = hfsplus_dir_release,
 584 };