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