linux/fs/hfs/inode.c
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   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
  21static const struct file_operations hfs_file_operations;
  22static 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
  28static int hfs_writepage(struct page *page, struct writeback_control *wbc)
  29{
  30        return block_write_full_page(page, hfs_get_block, wbc);
  31}
  32
  33static int hfs_readpage(struct file *file, struct page *page)
  34{
  35        return block_read_full_page(page, hfs_get_block);
  36}
  37
  38static void hfs_write_failed(struct address_space *mapping, loff_t to)
  39{
  40        struct inode *inode = mapping->host;
  41
  42        if (to > inode->i_size) {
  43                truncate_pagecache(inode, to, inode->i_size);
  44                hfs_file_truncate(inode);
  45        }
  46}
  47
  48static int hfs_write_begin(struct file *file, struct address_space *mapping,
  49                        loff_t pos, unsigned len, unsigned flags,
  50                        struct page **pagep, void **fsdata)
  51{
  52        int ret;
  53
  54        *pagep = NULL;
  55        ret = cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
  56                                hfs_get_block,
  57                                &HFS_I(mapping->host)->phys_size);
  58        if (unlikely(ret))
  59                hfs_write_failed(mapping, pos + len);
  60
  61        return ret;
  62}
  63
  64static sector_t hfs_bmap(struct address_space *mapping, sector_t block)
  65{
  66        return generic_block_bmap(mapping, block, hfs_get_block);
  67}
  68
  69static int hfs_releasepage(struct page *page, gfp_t mask)
  70{
  71        struct inode *inode = page->mapping->host;
  72        struct super_block *sb = inode->i_sb;
  73        struct hfs_btree *tree;
  74        struct hfs_bnode *node;
  75        u32 nidx;
  76        int i, res = 1;
  77
  78        switch (inode->i_ino) {
  79        case HFS_EXT_CNID:
  80                tree = HFS_SB(sb)->ext_tree;
  81                break;
  82        case HFS_CAT_CNID:
  83                tree = HFS_SB(sb)->cat_tree;
  84                break;
  85        default:
  86                BUG();
  87                return 0;
  88        }
  89
  90        if (!tree)
  91                return 0;
  92
  93        if (tree->node_size >= PAGE_CACHE_SIZE) {
  94                nidx = page->index >> (tree->node_size_shift - PAGE_CACHE_SHIFT);
  95                spin_lock(&tree->hash_lock);
  96                node = hfs_bnode_findhash(tree, nidx);
  97                if (!node)
  98                        ;
  99                else if (atomic_read(&node->refcnt))
 100                        res = 0;
 101                if (res && node) {
 102                        hfs_bnode_unhash(node);
 103                        hfs_bnode_free(node);
 104                }
 105                spin_unlock(&tree->hash_lock);
 106        } else {
 107                nidx = page->index << (PAGE_CACHE_SHIFT - tree->node_size_shift);
 108                i = 1 << (PAGE_CACHE_SHIFT - tree->node_size_shift);
 109                spin_lock(&tree->hash_lock);
 110                do {
 111                        node = hfs_bnode_findhash(tree, nidx++);
 112                        if (!node)
 113                                continue;
 114                        if (atomic_read(&node->refcnt)) {
 115                                res = 0;
 116                                break;
 117                        }
 118                        hfs_bnode_unhash(node);
 119                        hfs_bnode_free(node);
 120                } while (--i && nidx < tree->node_count);
 121                spin_unlock(&tree->hash_lock);
 122        }
 123        return res ? try_to_free_buffers(page) : 0;
 124}
 125
 126static ssize_t hfs_direct_IO(int rw, struct kiocb *iocb,
 127                const struct iovec *iov, loff_t offset, unsigned long nr_segs)
 128{
 129        struct file *file = iocb->ki_filp;
 130        struct address_space *mapping = file->f_mapping;
 131        struct inode *inode = file->f_path.dentry->d_inode->i_mapping->host;
 132        ssize_t ret;
 133
 134        ret = blockdev_direct_IO(rw, iocb, inode, iov, offset, nr_segs,
 135                                 hfs_get_block);
 136
 137        /*
 138         * In case of error extending write may have instantiated a few
 139         * blocks outside i_size. Trim these off again.
 140         */
 141        if (unlikely((rw & WRITE) && ret < 0)) {
 142                loff_t isize = i_size_read(inode);
 143                loff_t end = offset + iov_length(iov, nr_segs);
 144
 145                if (end > isize)
 146                        hfs_write_failed(mapping, end);
 147        }
 148
 149        return ret;
 150}
 151
 152static int hfs_writepages(struct address_space *mapping,
 153                          struct writeback_control *wbc)
 154{
 155        return mpage_writepages(mapping, wbc, hfs_get_block);
 156}
 157
 158const struct address_space_operations hfs_btree_aops = {
 159        .readpage       = hfs_readpage,
 160        .writepage      = hfs_writepage,
 161        .write_begin    = hfs_write_begin,
 162        .write_end      = generic_write_end,
 163        .bmap           = hfs_bmap,
 164        .releasepage    = hfs_releasepage,
 165};
 166
 167const struct address_space_operations hfs_aops = {
 168        .readpage       = hfs_readpage,
 169        .writepage      = hfs_writepage,
 170        .write_begin    = hfs_write_begin,
 171        .write_end      = generic_write_end,
 172        .bmap           = hfs_bmap,
 173        .direct_IO      = hfs_direct_IO,
 174        .writepages     = hfs_writepages,
 175};
 176
 177/*
 178 * hfs_new_inode
 179 */
 180struct inode *hfs_new_inode(struct inode *dir, struct qstr *name, umode_t mode)
 181{
 182        struct super_block *sb = dir->i_sb;
 183        struct inode *inode = new_inode(sb);
 184        if (!inode)
 185                return NULL;
 186
 187        mutex_init(&HFS_I(inode)->extents_lock);
 188        INIT_LIST_HEAD(&HFS_I(inode)->open_dir_list);
 189        hfs_cat_build_key(sb, (btree_key *)&HFS_I(inode)->cat_key, dir->i_ino, name);
 190        inode->i_ino = HFS_SB(sb)->next_id++;
 191        inode->i_mode = mode;
 192        inode->i_uid = current_fsuid();
 193        inode->i_gid = current_fsgid();
 194        set_nlink(inode, 1);
 195        inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME_SEC;
 196        HFS_I(inode)->flags = 0;
 197        HFS_I(inode)->rsrc_inode = NULL;
 198        HFS_I(inode)->fs_blocks = 0;
 199        if (S_ISDIR(mode)) {
 200                inode->i_size = 2;
 201                HFS_SB(sb)->folder_count++;
 202                if (dir->i_ino == HFS_ROOT_CNID)
 203                        HFS_SB(sb)->root_dirs++;
 204                inode->i_op = &hfs_dir_inode_operations;
 205                inode->i_fop = &hfs_dir_operations;
 206                inode->i_mode |= S_IRWXUGO;
 207                inode->i_mode &= ~HFS_SB(inode->i_sb)->s_dir_umask;
 208        } else if (S_ISREG(mode)) {
 209                HFS_I(inode)->clump_blocks = HFS_SB(sb)->clumpablks;
 210                HFS_SB(sb)->file_count++;
 211                if (dir->i_ino == HFS_ROOT_CNID)
 212                        HFS_SB(sb)->root_files++;
 213                inode->i_op = &hfs_file_inode_operations;
 214                inode->i_fop = &hfs_file_operations;
 215                inode->i_mapping->a_ops = &hfs_aops;
 216                inode->i_mode |= S_IRUGO|S_IXUGO;
 217                if (mode & S_IWUSR)
 218                        inode->i_mode |= S_IWUGO;
 219                inode->i_mode &= ~HFS_SB(inode->i_sb)->s_file_umask;
 220                HFS_I(inode)->phys_size = 0;
 221                HFS_I(inode)->alloc_blocks = 0;
 222                HFS_I(inode)->first_blocks = 0;
 223                HFS_I(inode)->cached_start = 0;
 224                HFS_I(inode)->cached_blocks = 0;
 225                memset(HFS_I(inode)->first_extents, 0, sizeof(hfs_extent_rec));
 226                memset(HFS_I(inode)->cached_extents, 0, sizeof(hfs_extent_rec));
 227        }
 228        insert_inode_hash(inode);
 229        mark_inode_dirty(inode);
 230        set_bit(HFS_FLG_MDB_DIRTY, &HFS_SB(sb)->flags);
 231        hfs_mark_mdb_dirty(sb);
 232
 233        return inode;
 234}
 235
 236void hfs_delete_inode(struct inode *inode)
 237{
 238        struct super_block *sb = inode->i_sb;
 239
 240        dprint(DBG_INODE, "delete_inode: %lu\n", inode->i_ino);
 241        if (S_ISDIR(inode->i_mode)) {
 242                HFS_SB(sb)->folder_count--;
 243                if (HFS_I(inode)->cat_key.ParID == cpu_to_be32(HFS_ROOT_CNID))
 244                        HFS_SB(sb)->root_dirs--;
 245                set_bit(HFS_FLG_MDB_DIRTY, &HFS_SB(sb)->flags);
 246                hfs_mark_mdb_dirty(sb);
 247                return;
 248        }
 249        HFS_SB(sb)->file_count--;
 250        if (HFS_I(inode)->cat_key.ParID == cpu_to_be32(HFS_ROOT_CNID))
 251                HFS_SB(sb)->root_files--;
 252        if (S_ISREG(inode->i_mode)) {
 253                if (!inode->i_nlink) {
 254                        inode->i_size = 0;
 255                        hfs_file_truncate(inode);
 256                }
 257        }
 258        set_bit(HFS_FLG_MDB_DIRTY, &HFS_SB(sb)->flags);
 259        hfs_mark_mdb_dirty(sb);
 260}
 261
 262void hfs_inode_read_fork(struct inode *inode, struct hfs_extent *ext,
 263                         __be32 __log_size, __be32 phys_size, u32 clump_size)
 264{
 265        struct super_block *sb = inode->i_sb;
 266        u32 log_size = be32_to_cpu(__log_size);
 267        u16 count;
 268        int i;
 269
 270        memcpy(HFS_I(inode)->first_extents, ext, sizeof(hfs_extent_rec));
 271        for (count = 0, i = 0; i < 3; i++)
 272                count += be16_to_cpu(ext[i].count);
 273        HFS_I(inode)->first_blocks = count;
 274
 275        inode->i_size = HFS_I(inode)->phys_size = log_size;
 276        HFS_I(inode)->fs_blocks = (log_size + sb->s_blocksize - 1) >> sb->s_blocksize_bits;
 277        inode_set_bytes(inode, HFS_I(inode)->fs_blocks << sb->s_blocksize_bits);
 278        HFS_I(inode)->alloc_blocks = be32_to_cpu(phys_size) /
 279                                     HFS_SB(sb)->alloc_blksz;
 280        HFS_I(inode)->clump_blocks = clump_size / HFS_SB(sb)->alloc_blksz;
 281        if (!HFS_I(inode)->clump_blocks)
 282                HFS_I(inode)->clump_blocks = HFS_SB(sb)->clumpablks;
 283}
 284
 285struct hfs_iget_data {
 286        struct hfs_cat_key *key;
 287        hfs_cat_rec *rec;
 288};
 289
 290static int hfs_test_inode(struct inode *inode, void *data)
 291{
 292        struct hfs_iget_data *idata = data;
 293        hfs_cat_rec *rec;
 294
 295        rec = idata->rec;
 296        switch (rec->type) {
 297        case HFS_CDR_DIR:
 298                return inode->i_ino == be32_to_cpu(rec->dir.DirID);
 299        case HFS_CDR_FIL:
 300                return inode->i_ino == be32_to_cpu(rec->file.FlNum);
 301        default:
 302                BUG();
 303                return 1;
 304        }
 305}
 306
 307/*
 308 * hfs_read_inode
 309 */
 310static int hfs_read_inode(struct inode *inode, void *data)
 311{
 312        struct hfs_iget_data *idata = data;
 313        struct hfs_sb_info *hsb = HFS_SB(inode->i_sb);
 314        hfs_cat_rec *rec;
 315
 316        HFS_I(inode)->flags = 0;
 317        HFS_I(inode)->rsrc_inode = NULL;
 318        mutex_init(&HFS_I(inode)->extents_lock);
 319        INIT_LIST_HEAD(&HFS_I(inode)->open_dir_list);
 320
 321        /* Initialize the inode */
 322        inode->i_uid = hsb->s_uid;
 323        inode->i_gid = hsb->s_gid;
 324        set_nlink(inode, 1);
 325
 326        if (idata->key)
 327                HFS_I(inode)->cat_key = *idata->key;
 328        else
 329                HFS_I(inode)->flags |= HFS_FLG_RSRC;
 330        HFS_I(inode)->tz_secondswest = sys_tz.tz_minuteswest * 60;
 331
 332        rec = idata->rec;
 333        switch (rec->type) {
 334        case HFS_CDR_FIL:
 335                if (!HFS_IS_RSRC(inode)) {
 336                        hfs_inode_read_fork(inode, rec->file.ExtRec, rec->file.LgLen,
 337                                            rec->file.PyLen, be16_to_cpu(rec->file.ClpSize));
 338                } else {
 339                        hfs_inode_read_fork(inode, rec->file.RExtRec, rec->file.RLgLen,
 340                                            rec->file.RPyLen, be16_to_cpu(rec->file.ClpSize));
 341                }
 342
 343                inode->i_ino = be32_to_cpu(rec->file.FlNum);
 344                inode->i_mode = S_IRUGO | S_IXUGO;
 345                if (!(rec->file.Flags & HFS_FIL_LOCK))
 346                        inode->i_mode |= S_IWUGO;
 347                inode->i_mode &= ~hsb->s_file_umask;
 348                inode->i_mode |= S_IFREG;
 349                inode->i_ctime = inode->i_atime = inode->i_mtime =
 350                                hfs_m_to_utime(rec->file.MdDat);
 351                inode->i_op = &hfs_file_inode_operations;
 352                inode->i_fop = &hfs_file_operations;
 353                inode->i_mapping->a_ops = &hfs_aops;
 354                break;
 355        case HFS_CDR_DIR:
 356                inode->i_ino = be32_to_cpu(rec->dir.DirID);
 357                inode->i_size = be16_to_cpu(rec->dir.Val) + 2;
 358                HFS_I(inode)->fs_blocks = 0;
 359                inode->i_mode = S_IFDIR | (S_IRWXUGO & ~hsb->s_dir_umask);
 360                inode->i_ctime = inode->i_atime = inode->i_mtime =
 361                                hfs_m_to_utime(rec->dir.MdDat);
 362                inode->i_op = &hfs_dir_inode_operations;
 363                inode->i_fop = &hfs_dir_operations;
 364                break;
 365        default:
 366                make_bad_inode(inode);
 367        }
 368        return 0;
 369}
 370
 371/*
 372 * __hfs_iget()
 373 *
 374 * Given the MDB for a HFS filesystem, a 'key' and an 'entry' in
 375 * the catalog B-tree and the 'type' of the desired file return the
 376 * inode for that file/directory or NULL.  Note that 'type' indicates
 377 * whether we want the actual file or directory, or the corresponding
 378 * metadata (AppleDouble header file or CAP metadata file).
 379 */
 380struct inode *hfs_iget(struct super_block *sb, struct hfs_cat_key *key, hfs_cat_rec *rec)
 381{
 382        struct hfs_iget_data data = { key, rec };
 383        struct inode *inode;
 384        u32 cnid;
 385
 386        switch (rec->type) {
 387        case HFS_CDR_DIR:
 388                cnid = be32_to_cpu(rec->dir.DirID);
 389                break;
 390        case HFS_CDR_FIL:
 391                cnid = be32_to_cpu(rec->file.FlNum);
 392                break;
 393        default:
 394                return NULL;
 395        }
 396        inode = iget5_locked(sb, cnid, hfs_test_inode, hfs_read_inode, &data);
 397        if (inode && (inode->i_state & I_NEW))
 398                unlock_new_inode(inode);
 399        return inode;
 400}
 401
 402void hfs_inode_write_fork(struct inode *inode, struct hfs_extent *ext,
 403                          __be32 *log_size, __be32 *phys_size)
 404{
 405        memcpy(ext, HFS_I(inode)->first_extents, sizeof(hfs_extent_rec));
 406
 407        if (log_size)
 408                *log_size = cpu_to_be32(inode->i_size);
 409        if (phys_size)
 410                *phys_size = cpu_to_be32(HFS_I(inode)->alloc_blocks *
 411                                         HFS_SB(inode->i_sb)->alloc_blksz);
 412}
 413
 414int hfs_write_inode(struct inode *inode, struct writeback_control *wbc)
 415{
 416        struct inode *main_inode = inode;
 417        struct hfs_find_data fd;
 418        hfs_cat_rec rec;
 419
 420        dprint(DBG_INODE, "hfs_write_inode: %lu\n", inode->i_ino);
 421        hfs_ext_write_extent(inode);
 422
 423        if (inode->i_ino < HFS_FIRSTUSER_CNID) {
 424                switch (inode->i_ino) {
 425                case HFS_ROOT_CNID:
 426                        break;
 427                case HFS_EXT_CNID:
 428                        hfs_btree_write(HFS_SB(inode->i_sb)->ext_tree);
 429                        return 0;
 430                case HFS_CAT_CNID:
 431                        hfs_btree_write(HFS_SB(inode->i_sb)->cat_tree);
 432                        return 0;
 433                default:
 434                        BUG();
 435                        return -EIO;
 436                }
 437        }
 438
 439        if (HFS_IS_RSRC(inode))
 440                main_inode = HFS_I(inode)->rsrc_inode;
 441
 442        if (!main_inode->i_nlink)
 443                return 0;
 444
 445        if (hfs_find_init(HFS_SB(main_inode->i_sb)->cat_tree, &fd))
 446                /* panic? */
 447                return -EIO;
 448
 449        fd.search_key->cat = HFS_I(main_inode)->cat_key;
 450        if (hfs_brec_find(&fd))
 451                /* panic? */
 452                goto out;
 453
 454        if (S_ISDIR(main_inode->i_mode)) {
 455                if (fd.entrylength < sizeof(struct hfs_cat_dir))
 456                        /* panic? */;
 457                hfs_bnode_read(fd.bnode, &rec, fd.entryoffset,
 458                           sizeof(struct hfs_cat_dir));
 459                if (rec.type != HFS_CDR_DIR ||
 460                    be32_to_cpu(rec.dir.DirID) != inode->i_ino) {
 461                }
 462
 463                rec.dir.MdDat = hfs_u_to_mtime(inode->i_mtime);
 464                rec.dir.Val = cpu_to_be16(inode->i_size - 2);
 465
 466                hfs_bnode_write(fd.bnode, &rec, fd.entryoffset,
 467                            sizeof(struct hfs_cat_dir));
 468        } else if (HFS_IS_RSRC(inode)) {
 469                hfs_bnode_read(fd.bnode, &rec, fd.entryoffset,
 470                               sizeof(struct hfs_cat_file));
 471                hfs_inode_write_fork(inode, rec.file.RExtRec,
 472                                     &rec.file.RLgLen, &rec.file.RPyLen);
 473                hfs_bnode_write(fd.bnode, &rec, fd.entryoffset,
 474                                sizeof(struct hfs_cat_file));
 475        } else {
 476                if (fd.entrylength < sizeof(struct hfs_cat_file))
 477                        /* panic? */;
 478                hfs_bnode_read(fd.bnode, &rec, fd.entryoffset,
 479                           sizeof(struct hfs_cat_file));
 480                if (rec.type != HFS_CDR_FIL ||
 481                    be32_to_cpu(rec.file.FlNum) != inode->i_ino) {
 482                }
 483
 484                if (inode->i_mode & S_IWUSR)
 485                        rec.file.Flags &= ~HFS_FIL_LOCK;
 486                else
 487                        rec.file.Flags |= HFS_FIL_LOCK;
 488                hfs_inode_write_fork(inode, rec.file.ExtRec, &rec.file.LgLen, &rec.file.PyLen);
 489                rec.file.MdDat = hfs_u_to_mtime(inode->i_mtime);
 490
 491                hfs_bnode_write(fd.bnode, &rec, fd.entryoffset,
 492                            sizeof(struct hfs_cat_file));
 493        }
 494out:
 495        hfs_find_exit(&fd);
 496        return 0;
 497}
 498
 499static struct dentry *hfs_file_lookup(struct inode *dir, struct dentry *dentry,
 500                                      unsigned int flags)
 501{
 502        struct inode *inode = NULL;
 503        hfs_cat_rec rec;
 504        struct hfs_find_data fd;
 505        int res;
 506
 507        if (HFS_IS_RSRC(dir) || strcmp(dentry->d_name.name, "rsrc"))
 508                goto out;
 509
 510        inode = HFS_I(dir)->rsrc_inode;
 511        if (inode)
 512                goto out;
 513
 514        inode = new_inode(dir->i_sb);
 515        if (!inode)
 516                return ERR_PTR(-ENOMEM);
 517
 518        hfs_find_init(HFS_SB(dir->i_sb)->cat_tree, &fd);
 519        fd.search_key->cat = HFS_I(dir)->cat_key;
 520        res = hfs_brec_read(&fd, &rec, sizeof(rec));
 521        if (!res) {
 522                struct hfs_iget_data idata = { NULL, &rec };
 523                hfs_read_inode(inode, &idata);
 524        }
 525        hfs_find_exit(&fd);
 526        if (res) {
 527                iput(inode);
 528                return ERR_PTR(res);
 529        }
 530        HFS_I(inode)->rsrc_inode = dir;
 531        HFS_I(dir)->rsrc_inode = inode;
 532        igrab(dir);
 533        hlist_add_fake(&inode->i_hash);
 534        mark_inode_dirty(inode);
 535out:
 536        d_add(dentry, inode);
 537        return NULL;
 538}
 539
 540void hfs_evict_inode(struct inode *inode)
 541{
 542        truncate_inode_pages(&inode->i_data, 0);
 543        clear_inode(inode);
 544        if (HFS_IS_RSRC(inode) && HFS_I(inode)->rsrc_inode) {
 545                HFS_I(HFS_I(inode)->rsrc_inode)->rsrc_inode = NULL;
 546                iput(HFS_I(inode)->rsrc_inode);
 547        }
 548}
 549
 550static int hfs_file_open(struct inode *inode, struct file *file)
 551{
 552        if (HFS_IS_RSRC(inode))
 553                inode = HFS_I(inode)->rsrc_inode;
 554        atomic_inc(&HFS_I(inode)->opencnt);
 555        return 0;
 556}
 557
 558static int hfs_file_release(struct inode *inode, struct file *file)
 559{
 560        //struct super_block *sb = inode->i_sb;
 561
 562        if (HFS_IS_RSRC(inode))
 563                inode = HFS_I(inode)->rsrc_inode;
 564        if (atomic_dec_and_test(&HFS_I(inode)->opencnt)) {
 565                mutex_lock(&inode->i_mutex);
 566                hfs_file_truncate(inode);
 567                //if (inode->i_flags & S_DEAD) {
 568                //      hfs_delete_cat(inode->i_ino, HFSPLUS_SB(sb).hidden_dir, NULL);
 569                //      hfs_delete_inode(inode);
 570                //}
 571                mutex_unlock(&inode->i_mutex);
 572        }
 573        return 0;
 574}
 575
 576/*
 577 * hfs_notify_change()
 578 *
 579 * Based very closely on fs/msdos/inode.c by Werner Almesberger
 580 *
 581 * This is the notify_change() field in the super_operations structure
 582 * for HFS file systems.  The purpose is to take that changes made to
 583 * an inode and apply then in a filesystem-dependent manner.  In this
 584 * case the process has a few of tasks to do:
 585 *  1) prevent changes to the i_uid and i_gid fields.
 586 *  2) map file permissions to the closest allowable permissions
 587 *  3) Since multiple Linux files can share the same on-disk inode under
 588 *     HFS (for instance the data and resource forks of a file) a change
 589 *     to permissions must be applied to all other in-core inodes which
 590 *     correspond to the same HFS file.
 591 */
 592
 593int hfs_inode_setattr(struct dentry *dentry, struct iattr * attr)
 594{
 595        struct inode *inode = dentry->d_inode;
 596        struct hfs_sb_info *hsb = HFS_SB(inode->i_sb);
 597        int error;
 598
 599        error = inode_change_ok(inode, attr); /* basic permission checks */
 600        if (error)
 601                return error;
 602
 603        /* no uig/gid changes and limit which mode bits can be set */
 604        if (((attr->ia_valid & ATTR_UID) &&
 605             (!uid_eq(attr->ia_uid, hsb->s_uid))) ||
 606            ((attr->ia_valid & ATTR_GID) &&
 607             (!gid_eq(attr->ia_gid, hsb->s_gid))) ||
 608            ((attr->ia_valid & ATTR_MODE) &&
 609             ((S_ISDIR(inode->i_mode) &&
 610               (attr->ia_mode != inode->i_mode)) ||
 611              (attr->ia_mode & ~HFS_VALID_MODE_BITS)))) {
 612                return hsb->s_quiet ? 0 : error;
 613        }
 614
 615        if (attr->ia_valid & ATTR_MODE) {
 616                /* Only the 'w' bits can ever change and only all together. */
 617                if (attr->ia_mode & S_IWUSR)
 618                        attr->ia_mode = inode->i_mode | S_IWUGO;
 619                else
 620                        attr->ia_mode = inode->i_mode & ~S_IWUGO;
 621                attr->ia_mode &= S_ISDIR(inode->i_mode) ? ~hsb->s_dir_umask: ~hsb->s_file_umask;
 622        }
 623
 624        if ((attr->ia_valid & ATTR_SIZE) &&
 625            attr->ia_size != i_size_read(inode)) {
 626                inode_dio_wait(inode);
 627
 628                error = inode_newsize_ok(inode, attr->ia_size);
 629                if (error)
 630                        return error;
 631
 632                truncate_setsize(inode, attr->ia_size);
 633                hfs_file_truncate(inode);
 634        }
 635
 636        setattr_copy(inode, attr);
 637        mark_inode_dirty(inode);
 638        return 0;
 639}
 640
 641static int hfs_file_fsync(struct file *filp, loff_t start, loff_t end,
 642                          int datasync)
 643{
 644        struct inode *inode = filp->f_mapping->host;
 645        struct super_block * sb;
 646        int ret, err;
 647
 648        ret = filemap_write_and_wait_range(inode->i_mapping, start, end);
 649        if (ret)
 650                return ret;
 651        mutex_lock(&inode->i_mutex);
 652
 653        /* sync the inode to buffers */
 654        ret = write_inode_now(inode, 0);
 655
 656        /* sync the superblock to buffers */
 657        sb = inode->i_sb;
 658        flush_delayed_work(&HFS_SB(sb)->mdb_work);
 659        /* .. finally sync the buffers to disk */
 660        err = sync_blockdev(sb->s_bdev);
 661        if (!ret)
 662                ret = err;
 663        mutex_unlock(&inode->i_mutex);
 664        return ret;
 665}
 666
 667static const struct file_operations hfs_file_operations = {
 668        .llseek         = generic_file_llseek,
 669        .read           = do_sync_read,
 670        .aio_read       = generic_file_aio_read,
 671        .write          = do_sync_write,
 672        .aio_write      = generic_file_aio_write,
 673        .mmap           = generic_file_mmap,
 674        .splice_read    = generic_file_splice_read,
 675        .fsync          = hfs_file_fsync,
 676        .open           = hfs_file_open,
 677        .release        = hfs_file_release,
 678};
 679
 680static const struct inode_operations hfs_file_inode_operations = {
 681        .lookup         = hfs_file_lookup,
 682        .setattr        = hfs_inode_setattr,
 683        .setxattr       = hfs_setxattr,
 684        .getxattr       = hfs_getxattr,
 685        .listxattr      = hfs_listxattr,
 686};
 687