fs/hfs/inode.c

   1 /*
   2  *  linux/fs/hfs/inode.c
   3  *
   4  * Copyright (C) 1995-1997  Paul H. Hargrove
   5  * (C) 2003 Ardis Technologies <roman@ardistech.com>
   6  * This file may be distributed under the terms of the GNU General Public License.
   7  *
   8  * This file contains inode-related functions which do not depend on
   9  * which scheme is being used to represent forks.
  10  *
  11  * Based on the minix file system code, (C) 1991, 1992 by Linus Torvalds
  12  */
  13
  14 #include <linux/pagemap.h>
  15 #include <linux/mpage.h>
  16 #include <linux/sched.h>
  17
  18 #include "hfs_fs.h"
  19 #include "btree.h"
  20
  21 static const struct file_operations hfs_file_operations;
  22 static const struct inode_operations hfs_file_inode_operations;
  23
  24 /*================ Variable-like macros ================*/
  25
  26 #define HFS_VALID_MODE_BITS  (S_IFREG | S_IFDIR | S_IRWXUGO)
  27
  28 static int hfs_writepage(struct page *page, struct writeback_control *wbc)
  29 {
  30         return block_write_full_page(page, hfs_get_block, wbc);
  31 }
  32
  33 static int hfs_readpage(struct file *file, struct page *page)
  34 {
  35         return block_read_full_page(page, hfs_get_block);
  36 }
  37
  38 static int hfs_write_begin(struct file *file, struct address_space *mapping,
  39                         loff_t pos, unsigned len, unsigned flags,
  40                         struct page **pagep, void **fsdata)
  41 {
  42         *pagep = NULL;
  43         return cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
  44                                 hfs_get_block,
  45                                 &HFS_I(mapping->host)->phys_size);
  46 }
  47
  48 static sector_t hfs_bmap(struct address_space *mapping, sector_t block)
  49 {
  50         return generic_block_bmap(mapping, block, hfs_get_block);
  51 }
  52
  53 static int hfs_releasepage(struct page *page, gfp_t mask)
  54 {
  55         struct inode *inode = page->mapping->host;
  56         struct super_block *sb = inode->i_sb;
  57         struct hfs_btree *tree;
  58         struct hfs_bnode *node;
  59         u32 nidx;
  60         int i, res = 1;
  61
  62         switch (inode->i_ino) {
  63         case HFS_EXT_CNID:
  64                 tree = HFS_SB(sb)->ext_tree;
  65                 break;
  66         case HFS_CAT_CNID:
  67                 tree = HFS_SB(sb)->cat_tree;
  68                 break;
  69         default:
  70                 BUG();
  71                 return 0;
  72         }
  73         if (tree->node_size >= PAGE_CACHE_SIZE) {
  74                 nidx = page->index >> (tree->node_size_shift - PAGE_CACHE_SHIFT);
  75                 spin_lock(&tree->hash_lock);
  76                 node = hfs_bnode_findhash(tree, nidx);
  77                 if (!node)
  78                         ;
  79                 else if (atomic_read(&node->refcnt))
  80                         res = 0;
  81                 if (res && node) {
  82                         hfs_bnode_unhash(node);
  83                         hfs_bnode_free(node);
  84                 }
  85                 spin_unlock(&tree->hash_lock);
  86         } else {
  87                 nidx = page->index << (PAGE_CACHE_SHIFT - tree->node_size_shift);
  88                 i = 1 << (PAGE_CACHE_SHIFT - tree->node_size_shift);
  89                 spin_lock(&tree->hash_lock);
  90                 do {
  91                         node = hfs_bnode_findhash(tree, nidx++);
  92                         if (!node)
  93                                 continue;
  94                         if (atomic_read(&node->refcnt)) {
  95                                 res = 0;
  96                                 break;
  97                         }
  98                         hfs_bnode_unhash(node);
  99                         hfs_bnode_free(node);
 100                 } while (--i && nidx < tree->node_count);
 101                 spin_unlock(&tree->hash_lock);
 102         }
 103         return res ? try_to_free_buffers(page) : 0;
 104 }
 105
 106 static ssize_t hfs_direct_IO(int rw, struct kiocb *iocb,
 107                 const struct iovec *iov, loff_t offset, unsigned long nr_segs)
 108 {
 109         struct file *file = iocb->ki_filp;
 110         struct inode *inode = file->f_path.dentry->d_inode->i_mapping->host;
 111
 112         return blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev, iov,
 113                                   offset, nr_segs, hfs_get_block, NULL);
 114 }
 115
 116 static int hfs_writepages(struct address_space *mapping,
 117                           struct writeback_control *wbc)
 118 {
 119         return mpage_writepages(mapping, wbc, hfs_get_block);
 120 }
 121
 122 const struct address_space_operations hfs_btree_aops = {
 123         .readpage       = hfs_readpage,
 124         .writepage      = hfs_writepage,
 125         .sync_page      = block_sync_page,
 126         .write_begin    = hfs_write_begin,
 127         .write_end      = generic_write_end,
 128         .bmap           = hfs_bmap,
 129         .releasepage    = hfs_releasepage,
 130 };
 131
 132 const struct address_space_operations hfs_aops = {
 133         .readpage       = hfs_readpage,
 134         .writepage      = hfs_writepage,
 135         .sync_page      = block_sync_page,
 136         .write_begin    = hfs_write_begin,
 137         .write_end      = generic_write_end,
 138         .bmap           = hfs_bmap,
 139         .direct_IO      = hfs_direct_IO,
 140         .writepages     = hfs_writepages,
 141 };
 142
 143 /*
 144  * hfs_new_inode
 145  */
 146 struct inode *hfs_new_inode(struct inode *dir, struct qstr *name, int mode)
 147 {
 148         struct super_block *sb = dir->i_sb;
 149         struct inode *inode = new_inode(sb);
 150         if (!inode)
 151                 return NULL;
 152
 153         init_MUTEX(&HFS_I(inode)->extents_lock);
 154         INIT_LIST_HEAD(&HFS_I(inode)->open_dir_list);
 155         hfs_cat_build_key(sb, (btree_key *)&HFS_I(inode)->cat_key, dir->i_ino, name);
 156         inode->i_ino = HFS_SB(sb)->next_id++;
 157         inode->i_mode = mode;
 158         inode->i_uid = current->fsuid;
 159         inode->i_gid = current->fsgid;
 160         inode->i_nlink = 1;
 161         inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME_SEC;
 162         HFS_I(inode)->flags = 0;
 163         HFS_I(inode)->rsrc_inode = NULL;
 164         HFS_I(inode)->fs_blocks = 0;
 165         if (S_ISDIR(mode)) {
 166                 inode->i_size = 2;
 167                 HFS_SB(sb)->folder_count++;
 168                 if (dir->i_ino == HFS_ROOT_CNID)
 169                         HFS_SB(sb)->root_dirs++;
 170                 inode->i_op = &hfs_dir_inode_operations;
 171                 inode->i_fop = &hfs_dir_operations;
 172                 inode->i_mode |= S_IRWXUGO;
 173                 inode->i_mode &= ~HFS_SB(inode->i_sb)->s_dir_umask;
 174         } else if (S_ISREG(mode)) {
 175                 HFS_I(inode)->clump_blocks = HFS_SB(sb)->clumpablks;
 176                 HFS_SB(sb)->file_count++;
 177                 if (dir->i_ino == HFS_ROOT_CNID)
 178                         HFS_SB(sb)->root_files++;
 179                 inode->i_op = &hfs_file_inode_operations;
 180                 inode->i_fop = &hfs_file_operations;
 181                 inode->i_mapping->a_ops = &hfs_aops;
 182                 inode->i_mode |= S_IRUGO|S_IXUGO;
 183                 if (mode & S_IWUSR)
 184                         inode->i_mode |= S_IWUGO;
 185                 inode->i_mode &= ~HFS_SB(inode->i_sb)->s_file_umask;
 186                 HFS_I(inode)->phys_size = 0;
 187                 HFS_I(inode)->alloc_blocks = 0;
 188                 HFS_I(inode)->first_blocks = 0;
 189                 HFS_I(inode)->cached_start = 0;
 190                 HFS_I(inode)->cached_blocks = 0;
 191                 memset(HFS_I(inode)->first_extents, 0, sizeof(hfs_extent_rec));
 192                 memset(HFS_I(inode)->cached_extents, 0, sizeof(hfs_extent_rec));
 193         }
 194         insert_inode_hash(inode);
 195         mark_inode_dirty(inode);
 196         set_bit(HFS_FLG_MDB_DIRTY, &HFS_SB(sb)->flags);
 197         sb->s_dirt = 1;
 198
 199         return inode;
 200 }
 201
 202 void hfs_delete_inode(struct inode *inode)
 203 {
 204         struct super_block *sb = inode->i_sb;
 205
 206         dprint(DBG_INODE, "delete_inode: %lu\n", inode->i_ino);
 207         if (S_ISDIR(inode->i_mode)) {
 208                 HFS_SB(sb)->folder_count--;
 209                 if (HFS_I(inode)->cat_key.ParID == cpu_to_be32(HFS_ROOT_CNID))
 210                         HFS_SB(sb)->root_dirs--;
 211                 set_bit(HFS_FLG_MDB_DIRTY, &HFS_SB(sb)->flags);
 212                 sb->s_dirt = 1;
 213                 return;
 214         }
 215         HFS_SB(sb)->file_count--;
 216         if (HFS_I(inode)->cat_key.ParID == cpu_to_be32(HFS_ROOT_CNID))
 217                 HFS_SB(sb)->root_files--;
 218         if (S_ISREG(inode->i_mode)) {
 219                 if (!inode->i_nlink) {
 220                         inode->i_size = 0;
 221                         hfs_file_truncate(inode);
 222                 }
 223         }
 224         set_bit(HFS_FLG_MDB_DIRTY, &HFS_SB(sb)->flags);
 225         sb->s_dirt = 1;
 226 }
 227
 228 void hfs_inode_read_fork(struct inode *inode, struct hfs_extent *ext,
 229                          __be32 __log_size, __be32 phys_size, u32 clump_size)
 230 {
 231         struct super_block *sb = inode->i_sb;
 232         u32 log_size = be32_to_cpu(__log_size);
 233         u16 count;
 234         int i;
 235
 236         memcpy(HFS_I(inode)->first_extents, ext, sizeof(hfs_extent_rec));
 237         for (count = 0, i = 0; i < 3; i++)
 238                 count += be16_to_cpu(ext[i].count);
 239         HFS_I(inode)->first_blocks = count;
 240
 241         inode->i_size = HFS_I(inode)->phys_size = log_size;
 242         HFS_I(inode)->fs_blocks = (log_size + sb->s_blocksize - 1) >> sb->s_blocksize_bits;
 243         inode_set_bytes(inode, HFS_I(inode)->fs_blocks << sb->s_blocksize_bits);
 244         HFS_I(inode)->alloc_blocks = be32_to_cpu(phys_size) /
 245                                      HFS_SB(sb)->alloc_blksz;
 246         HFS_I(inode)->clump_blocks = clump_size / HFS_SB(sb)->alloc_blksz;
 247         if (!HFS_I(inode)->clump_blocks)
 248                 HFS_I(inode)->clump_blocks = HFS_SB(sb)->clumpablks;
 249 }
 250
 251 struct hfs_iget_data {
 252         struct hfs_cat_key *key;
 253         hfs_cat_rec *rec;
 254 };
 255
 256 static int hfs_test_inode(struct inode *inode, void *data)
 257 {
 258         struct hfs_iget_data *idata = data;
 259         hfs_cat_rec *rec;
 260
 261         rec = idata->rec;
 262         switch (rec->type) {
 263         case HFS_CDR_DIR:
 264                 return inode->i_ino == be32_to_cpu(rec->dir.DirID);
 265         case HFS_CDR_FIL:
 266                 return inode->i_ino == be32_to_cpu(rec->file.FlNum);
 267         default:
 268                 BUG();
 269                 return 1;
 270         }
 271 }
 272
 273 /*
 274  * hfs_read_inode
 275  */
 276 static int hfs_read_inode(struct inode *inode, void *data)
 277 {
 278         struct hfs_iget_data *idata = data;
 279         struct hfs_sb_info *hsb = HFS_SB(inode->i_sb);
 280         hfs_cat_rec *rec;
 281
 282         HFS_I(inode)->flags = 0;
 283         HFS_I(inode)->rsrc_inode = NULL;
 284         init_MUTEX(&HFS_I(inode)->extents_lock);
 285         INIT_LIST_HEAD(&HFS_I(inode)->open_dir_list);
 286
 287         /* Initialize the inode */
 288         inode->i_uid = hsb->s_uid;
 289         inode->i_gid = hsb->s_gid;
 290         inode->i_nlink = 1;
 291
 292         if (idata->key)
 293                 HFS_I(inode)->cat_key = *idata->key;
 294         else
 295                 HFS_I(inode)->flags |= HFS_FLG_RSRC;
 296         HFS_I(inode)->tz_secondswest = sys_tz.tz_minuteswest * 60;
 297
 298         rec = idata->rec;
 299         switch (rec->type) {
 300         case HFS_CDR_FIL:
 301                 if (!HFS_IS_RSRC(inode)) {
 302                         hfs_inode_read_fork(inode, rec->file.ExtRec, rec->file.LgLen,
 303                                             rec->file.PyLen, be16_to_cpu(rec->file.ClpSize));
 304                 } else {
 305                         hfs_inode_read_fork(inode, rec->file.RExtRec, rec->file.RLgLen,
 306                                             rec->file.RPyLen, be16_to_cpu(rec->file.ClpSize));
 307                 }
 308
 309                 inode->i_ino = be32_to_cpu(rec->file.FlNum);
 310                 inode->i_mode = S_IRUGO | S_IXUGO;
 311                 if (!(rec->file.Flags & HFS_FIL_LOCK))
 312                         inode->i_mode |= S_IWUGO;
 313                 inode->i_mode &= ~hsb->s_file_umask;
 314                 inode->i_mode |= S_IFREG;
 315                 inode->i_ctime = inode->i_atime = inode->i_mtime =
 316                                 hfs_m_to_utime(rec->file.MdDat);
 317                 inode->i_op = &hfs_file_inode_operations;
 318                 inode->i_fop = &hfs_file_operations;
 319                 inode->i_mapping->a_ops = &hfs_aops;
 320                 break;
 321         case HFS_CDR_DIR:
 322                 inode->i_ino = be32_to_cpu(rec->dir.DirID);
 323                 inode->i_size = be16_to_cpu(rec->dir.Val) + 2;
 324                 HFS_I(inode)->fs_blocks = 0;
 325                 inode->i_mode = S_IFDIR | (S_IRWXUGO & ~hsb->s_dir_umask);
 326                 inode->i_ctime = inode->i_atime = inode->i_mtime =
 327                                 hfs_m_to_utime(rec->dir.MdDat);
 328                 inode->i_op = &hfs_dir_inode_operations;
 329                 inode->i_fop = &hfs_dir_operations;
 330                 break;
 331         default:
 332                 make_bad_inode(inode);
 333         }
 334         return 0;
 335 }
 336
 337 /*
 338  * __hfs_iget()
 339  *
 340  * Given the MDB for a HFS filesystem, a 'key' and an 'entry' in
 341  * the catalog B-tree and the 'type' of the desired file return the
 342  * inode for that file/directory or NULL.  Note that 'type' indicates
 343  * whether we want the actual file or directory, or the corresponding
 344  * metadata (AppleDouble header file or CAP metadata file).
 345  */
 346 struct inode *hfs_iget(struct super_block *sb, struct hfs_cat_key *key, hfs_cat_rec *rec)
 347 {
 348         struct hfs_iget_data data = { key, rec };
 349         struct inode *inode;
 350         u32 cnid;
 351
 352         switch (rec->type) {
 353         case HFS_CDR_DIR:
 354                 cnid = be32_to_cpu(rec->dir.DirID);
 355                 break;
 356         case HFS_CDR_FIL:
 357                 cnid = be32_to_cpu(rec->file.FlNum);
 358                 break;
 359         default:
 360                 return NULL;
 361         }
 362         inode = iget5_locked(sb, cnid, hfs_test_inode, hfs_read_inode, &data);
 363         if (inode && (inode->i_state & I_NEW))
 364                 unlock_new_inode(inode);
 365         return inode;
 366 }
 367
 368 void hfs_inode_write_fork(struct inode *inode, struct hfs_extent *ext,
 369                           __be32 *log_size, __be32 *phys_size)
 370 {
 371         memcpy(ext, HFS_I(inode)->first_extents, sizeof(hfs_extent_rec));
 372
 373         if (log_size)
 374                 *log_size = cpu_to_be32(inode->i_size);
 375         if (phys_size)
 376                 *phys_size = cpu_to_be32(HFS_I(inode)->alloc_blocks *
 377                                          HFS_SB(inode->i_sb)->alloc_blksz);
 378 }
 379
 380 int hfs_write_inode(struct inode *inode, int unused)
 381 {
 382         struct inode *main_inode = inode;
 383         struct hfs_find_data fd;
 384         hfs_cat_rec rec;
 385
 386         dprint(DBG_INODE, "hfs_write_inode: %lu\n", inode->i_ino);
 387         hfs_ext_write_extent(inode);
 388
 389         if (inode->i_ino < HFS_FIRSTUSER_CNID) {
 390                 switch (inode->i_ino) {
 391                 case HFS_ROOT_CNID:
 392                         break;
 393                 case HFS_EXT_CNID:
 394                         hfs_btree_write(HFS_SB(inode->i_sb)->ext_tree);
 395                         return 0;
 396                 case HFS_CAT_CNID:
 397                         hfs_btree_write(HFS_SB(inode->i_sb)->cat_tree);
 398                         return 0;
 399                 default:
 400                         BUG();
 401                         return -EIO;
 402                 }
 403         }
 404
 405         if (HFS_IS_RSRC(inode))
 406                 main_inode = HFS_I(inode)->rsrc_inode;
 407
 408         if (!main_inode->i_nlink)
 409                 return 0;
 410
 411         if (hfs_find_init(HFS_SB(main_inode->i_sb)->cat_tree, &fd))
 412                 /* panic? */
 413                 return -EIO;
 414
 415         fd.search_key->cat = HFS_I(main_inode)->cat_key;
 416         if (hfs_brec_find(&fd))
 417                 /* panic? */
 418                 goto out;
 419
 420         if (S_ISDIR(main_inode->i_mode)) {
 421                 if (fd.entrylength < sizeof(struct hfs_cat_dir))
 422                         /* panic? */;
 423                 hfs_bnode_read(fd.bnode, &rec, fd.entryoffset,
 424                            sizeof(struct hfs_cat_dir));
 425                 if (rec.type != HFS_CDR_DIR ||
 426                     be32_to_cpu(rec.dir.DirID) != inode->i_ino) {
 427                 }
 428
 429                 rec.dir.MdDat = hfs_u_to_mtime(inode->i_mtime);
 430                 rec.dir.Val = cpu_to_be16(inode->i_size - 2);
 431
 432                 hfs_bnode_write(fd.bnode, &rec, fd.entryoffset,
 433                             sizeof(struct hfs_cat_dir));
 434         } else if (HFS_IS_RSRC(inode)) {
 435                 hfs_bnode_read(fd.bnode, &rec, fd.entryoffset,
 436                                sizeof(struct hfs_cat_file));
 437                 hfs_inode_write_fork(inode, rec.file.RExtRec,
 438                                      &rec.file.RLgLen, &rec.file.RPyLen);
 439                 hfs_bnode_write(fd.bnode, &rec, fd.entryoffset,
 440                                 sizeof(struct hfs_cat_file));
 441         } else {
 442                 if (fd.entrylength < sizeof(struct hfs_cat_file))
 443                         /* panic? */;
 444                 hfs_bnode_read(fd.bnode, &rec, fd.entryoffset,
 445                            sizeof(struct hfs_cat_file));
 446                 if (rec.type != HFS_CDR_FIL ||
 447                     be32_to_cpu(rec.file.FlNum) != inode->i_ino) {
 448                 }
 449
 450                 if (inode->i_mode & S_IWUSR)
 451                         rec.file.Flags &= ~HFS_FIL_LOCK;
 452                 else
 453                         rec.file.Flags |= HFS_FIL_LOCK;
 454                 hfs_inode_write_fork(inode, rec.file.ExtRec, &rec.file.LgLen, &rec.file.PyLen);
 455                 rec.file.MdDat = hfs_u_to_mtime(inode->i_mtime);
 456
 457                 hfs_bnode_write(fd.bnode, &rec, fd.entryoffset,
 458                             sizeof(struct hfs_cat_file));
 459         }
 460 out:
 461         hfs_find_exit(&fd);
 462         return 0;
 463 }
 464
 465 static struct dentry *hfs_file_lookup(struct inode *dir, struct dentry *dentry,
 466                                       struct nameidata *nd)
 467 {
 468         struct inode *inode = NULL;
 469         hfs_cat_rec rec;
 470         struct hfs_find_data fd;
 471         int res;
 472
 473         if (HFS_IS_RSRC(dir) || strcmp(dentry->d_name.name, "rsrc"))
 474                 goto out;
 475
 476         inode = HFS_I(dir)->rsrc_inode;
 477         if (inode)
 478                 goto out;
 479
 480         inode = new_inode(dir->i_sb);
 481         if (!inode)
 482                 return ERR_PTR(-ENOMEM);
 483
 484         hfs_find_init(HFS_SB(dir->i_sb)->cat_tree, &fd);
 485         fd.search_key->cat = HFS_I(dir)->cat_key;
 486         res = hfs_brec_read(&fd, &rec, sizeof(rec));
 487         if (!res) {
 488                 struct hfs_iget_data idata = { NULL, &rec };
 489                 hfs_read_inode(inode, &idata);
 490         }
 491         hfs_find_exit(&fd);
 492         if (res) {
 493                 iput(inode);
 494                 return ERR_PTR(res);
 495         }
 496         HFS_I(inode)->rsrc_inode = dir;
 497         HFS_I(dir)->rsrc_inode = inode;
 498         igrab(dir);
 499         hlist_add_head(&inode->i_hash, &HFS_SB(dir->i_sb)->rsrc_inodes);
 500         mark_inode_dirty(inode);
 501 out:
 502         d_add(dentry, inode);
 503         return NULL;
 504 }
 505
 506 void hfs_clear_inode(struct inode *inode)
 507 {
 508         if (HFS_IS_RSRC(inode) && HFS_I(inode)->rsrc_inode) {
 509                 HFS_I(HFS_I(inode)->rsrc_inode)->rsrc_inode = NULL;
 510                 iput(HFS_I(inode)->rsrc_inode);
 511         }
 512 }
 513
 514 static int hfs_permission(struct inode *inode, int mask,
 515                           struct nameidata *nd)
 516 {
 517         if (S_ISREG(inode->i_mode) && mask & MAY_EXEC)
 518                 return 0;
 519         return generic_permission(inode, mask, NULL);
 520 }
 521
 522 static int hfs_file_open(struct inode *inode, struct file *file)
 523 {
 524         if (HFS_IS_RSRC(inode))
 525                 inode = HFS_I(inode)->rsrc_inode;
 526         if (atomic_read(&file->f_count) != 1)
 527                 return 0;
 528         atomic_inc(&HFS_I(inode)->opencnt);
 529         return 0;
 530 }
 531
 532 static int hfs_file_release(struct inode *inode, struct file *file)
 533 {
 534         //struct super_block *sb = inode->i_sb;
 535
 536         if (HFS_IS_RSRC(inode))
 537                 inode = HFS_I(inode)->rsrc_inode;
 538         if (atomic_read(&file->f_count) != 0)
 539                 return 0;
 540         if (atomic_dec_and_test(&HFS_I(inode)->opencnt)) {
 541                 mutex_lock(&inode->i_mutex);
 542                 hfs_file_truncate(inode);
 543                 //if (inode->i_flags & S_DEAD) {
 544                 //      hfs_delete_cat(inode->i_ino, HFSPLUS_SB(sb).hidden_dir, NULL);
 545                 //      hfs_delete_inode(inode);
 546                 //}
 547                 mutex_unlock(&inode->i_mutex);
 548         }
 549         return 0;
 550 }
 551
 552 /*
 553  * hfs_notify_change()
 554  *
 555  * Based very closely on fs/msdos/inode.c by Werner Almesberger
 556  *
 557  * This is the notify_change() field in the super_operations structure
 558  * for HFS file systems.  The purpose is to take that changes made to
 559  * an inode and apply then in a filesystem-dependent manner.  In this
 560  * case the process has a few of tasks to do:
 561  *  1) prevent changes to the i_uid and i_gid fields.
 562  *  2) map file permissions to the closest allowable permissions
 563  *  3) Since multiple Linux files can share the same on-disk inode under
 564  *     HFS (for instance the data and resource forks of a file) a change
 565  *     to permissions must be applied to all other in-core inodes which
 566  *     correspond to the same HFS file.
 567  */
 568
 569 int hfs_inode_setattr(struct dentry *dentry, struct iattr * attr)
 570 {
 571         struct inode *inode = dentry->d_inode;
 572         struct hfs_sb_info *hsb = HFS_SB(inode->i_sb);
 573         int error;
 574
 575         error = inode_change_ok(inode, attr); /* basic permission checks */
 576         if (error)
 577                 return error;
 578
 579         /* no uig/gid changes and limit which mode bits can be set */
 580         if (((attr->ia_valid & ATTR_UID) &&
 581              (attr->ia_uid != hsb->s_uid)) ||
 582             ((attr->ia_valid & ATTR_GID) &&
 583              (attr->ia_gid != hsb->s_gid)) ||
 584             ((attr->ia_valid & ATTR_MODE) &&
 585              ((S_ISDIR(inode->i_mode) &&
 586                (attr->ia_mode != inode->i_mode)) ||
 587               (attr->ia_mode & ~HFS_VALID_MODE_BITS)))) {
 588                 return hsb->s_quiet ? 0 : error;
 589         }
 590
 591         if (attr->ia_valid & ATTR_MODE) {
 592                 /* Only the 'w' bits can ever change and only all together. */
 593                 if (attr->ia_mode & S_IWUSR)
 594                         attr->ia_mode = inode->i_mode | S_IWUGO;
 595                 else
 596                         attr->ia_mode = inode->i_mode & ~S_IWUGO;
 597                 attr->ia_mode &= S_ISDIR(inode->i_mode) ? ~hsb->s_dir_umask: ~hsb->s_file_umask;
 598         }
 599         error = inode_setattr(inode, attr);
 600         if (error)
 601                 return error;
 602
 603         return 0;
 604 }
 605
 606
 607 static const struct file_operations hfs_file_operations = {
 608         .llseek         = generic_file_llseek,
 609         .read           = do_sync_read,
 610         .aio_read       = generic_file_aio_read,
 611         .write          = do_sync_write,
 612         .aio_write      = generic_file_aio_write,
 613         .mmap           = generic_file_mmap,
 614         .splice_read    = generic_file_splice_read,
 615         .fsync          = file_fsync,
 616         .open           = hfs_file_open,
 617         .release        = hfs_file_release,
 618 };
 619
 620 static const struct inode_operations hfs_file_inode_operations = {
 621         .lookup         = hfs_file_lookup,
 622         .truncate       = hfs_file_truncate,
 623         .setattr        = hfs_inode_setattr,
 624         .permission     = hfs_permission,
 625         .setxattr       = hfs_setxattr,
 626         .getxattr       = hfs_getxattr,
 627         .listxattr      = hfs_listxattr,
 628 };