fs/hfsplus/dir.c

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