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