fs/hfsplus/xattr.c

   1 /*
   2  * linux/fs/hfsplus/xattr.c
   3  *
   4  * Vyacheslav Dubeyko <[email protected]>
   5  *
   6  * Logic of processing extended attributes
   7  */
   8
   9 #include "hfsplus_fs.h"
  10 #include <linux/posix_acl_xattr.h>
  11 #include <linux/nls.h>
  12 #include "xattr.h"
  13 #include "acl.h"
  14
  15 static int hfsplus_removexattr(struct inode *inode, const char *name);
  16
  17 const struct xattr_handler *hfsplus_xattr_handlers[] = {
  18         &hfsplus_xattr_osx_handler,
  19         &hfsplus_xattr_user_handler,
  20         &hfsplus_xattr_trusted_handler,
  21 #ifdef CONFIG_HFSPLUS_FS_POSIX_ACL
  22         &posix_acl_access_xattr_handler,
  23         &posix_acl_default_xattr_handler,
  24 #endif
  25         &hfsplus_xattr_security_handler,
  26         NULL
  27 };
  28
  29 static int strcmp_xattr_finder_info(const char *name)
  30 {
  31         if (name) {
  32                 return strncmp(name, HFSPLUS_XATTR_FINDER_INFO_NAME,
  33                                 sizeof(HFSPLUS_XATTR_FINDER_INFO_NAME));
  34         }
  35         return -1;
  36 }
  37
  38 static int strcmp_xattr_acl(const char *name)
  39 {
  40         if (name) {
  41                 return strncmp(name, HFSPLUS_XATTR_ACL_NAME,
  42                                 sizeof(HFSPLUS_XATTR_ACL_NAME));
  43         }
  44         return -1;
  45 }
  46
  47 static bool is_known_namespace(const char *name)
  48 {
  49         if (strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN) &&
  50             strncmp(name, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN) &&
  51             strncmp(name, XATTR_SECURITY_PREFIX, XATTR_SECURITY_PREFIX_LEN) &&
  52             strncmp(name, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN))
  53                 return false;
  54
  55         return true;
  56 }
  57
  58 static void hfsplus_init_header_node(struct inode *attr_file,
  59                                         u32 clump_size,
  60                                         char *buf, u16 node_size)
  61 {
  62         struct hfs_bnode_desc *desc;
  63         struct hfs_btree_header_rec *head;
  64         u16 offset;
  65         __be16 *rec_offsets;
  66         u32 hdr_node_map_rec_bits;
  67         char *bmp;
  68         u32 used_nodes;
  69         u32 used_bmp_bytes;
  70         u64 tmp;
  71
  72         hfs_dbg(ATTR_MOD, "init_hdr_attr_file: clump %u, node_size %u\n",
  73                 clump_size, node_size);
  74
  75         /* The end of the node contains list of record offsets */
  76         rec_offsets = (__be16 *)(buf + node_size);
  77
  78         desc = (struct hfs_bnode_desc *)buf;
  79         desc->type = HFS_NODE_HEADER;
  80         desc->num_recs = cpu_to_be16(HFSPLUS_BTREE_HDR_NODE_RECS_COUNT);
  81         offset = sizeof(struct hfs_bnode_desc);
  82         *--rec_offsets = cpu_to_be16(offset);
  83
  84         head = (struct hfs_btree_header_rec *)(buf + offset);
  85         head->node_size = cpu_to_be16(node_size);
  86         tmp = i_size_read(attr_file);
  87         do_div(tmp, node_size);
  88         head->node_count = cpu_to_be32(tmp);
  89         head->free_nodes = cpu_to_be32(be32_to_cpu(head->node_count) - 1);
  90         head->clump_size = cpu_to_be32(clump_size);
  91         head->attributes |= cpu_to_be32(HFS_TREE_BIGKEYS | HFS_TREE_VARIDXKEYS);
  92         head->max_key_len = cpu_to_be16(HFSPLUS_ATTR_KEYLEN - sizeof(u16));
  93         offset += sizeof(struct hfs_btree_header_rec);
  94         *--rec_offsets = cpu_to_be16(offset);
  95         offset += HFSPLUS_BTREE_HDR_USER_BYTES;
  96         *--rec_offsets = cpu_to_be16(offset);
  97
  98         hdr_node_map_rec_bits = 8 * (node_size - offset - (4 * sizeof(u16)));
  99         if (be32_to_cpu(head->node_count) > hdr_node_map_rec_bits) {
 100                 u32 map_node_bits;
 101                 u32 map_nodes;
 102
 103                 desc->next = cpu_to_be32(be32_to_cpu(head->leaf_tail) + 1);
 104                 map_node_bits = 8 * (node_size - sizeof(struct hfs_bnode_desc) -
 105                                         (2 * sizeof(u16)) - 2);
 106                 map_nodes = (be32_to_cpu(head->node_count) -
 107                                 hdr_node_map_rec_bits +
 108                                 (map_node_bits - 1)) / map_node_bits;
 109                 be32_add_cpu(&head->free_nodes, 0 - map_nodes);
 110         }
 111
 112         bmp = buf + offset;
 113         used_nodes =
 114                 be32_to_cpu(head->node_count) - be32_to_cpu(head->free_nodes);
 115         used_bmp_bytes = used_nodes / 8;
 116         if (used_bmp_bytes) {
 117                 memset(bmp, 0xFF, used_bmp_bytes);
 118                 bmp += used_bmp_bytes;
 119                 used_nodes %= 8;
 120         }
 121         *bmp = ~(0xFF >> used_nodes);
 122         offset += hdr_node_map_rec_bits / 8;
 123         *--rec_offsets = cpu_to_be16(offset);
 124 }
 125
 126 static int hfsplus_create_attributes_file(struct super_block *sb)
 127 {
 128         int err = 0;
 129         struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb);
 130         struct inode *attr_file;
 131         struct hfsplus_inode_info *hip;
 132         u32 clump_size;
 133         u16 node_size = HFSPLUS_ATTR_TREE_NODE_SIZE;
 134         char *buf;
 135         int index, written;
 136         struct address_space *mapping;
 137         struct page *page;
 138         int old_state = HFSPLUS_EMPTY_ATTR_TREE;
 139
 140         hfs_dbg(ATTR_MOD, "create_attr_file: ino %d\n", HFSPLUS_ATTR_CNID);
 141
 142 check_attr_tree_state_again:
 143         switch (atomic_read(&sbi->attr_tree_state)) {
 144         case HFSPLUS_EMPTY_ATTR_TREE:
 145                 if (old_state != atomic_cmpxchg(&sbi->attr_tree_state,
 146                                                 old_state,
 147                                                 HFSPLUS_CREATING_ATTR_TREE))
 148                         goto check_attr_tree_state_again;
 149                 break;
 150         case HFSPLUS_CREATING_ATTR_TREE:
 151                 /*
 152                  * This state means that another thread is in process
 153                  * of AttributesFile creation. Theoretically, it is
 154                  * possible to be here. But really __setxattr() method
 155                  * first of all calls hfs_find_init() for lookup in
 156                  * B-tree of CatalogFile. This method locks mutex of
 157                  * CatalogFile's B-tree. As a result, if some thread
 158                  * is inside AttributedFile creation operation then
 159                  * another threads will be waiting unlocking of
 160                  * CatalogFile's B-tree's mutex. However, if code will
 161                  * change then we will return error code (-EAGAIN) from
 162                  * here. Really, it means that first try to set of xattr
 163                  * fails with error but second attempt will have success.
 164                  */
 165                 return -EAGAIN;
 166         case HFSPLUS_VALID_ATTR_TREE:
 167                 return 0;
 168         case HFSPLUS_FAILED_ATTR_TREE:
 169                 return -EOPNOTSUPP;
 170         default:
 171                 BUG();
 172         }
 173
 174         attr_file = hfsplus_iget(sb, HFSPLUS_ATTR_CNID);
 175         if (IS_ERR(attr_file)) {
 176                 pr_err("failed to load attributes file\n");
 177                 return PTR_ERR(attr_file);
 178         }
 179
 180         BUG_ON(i_size_read(attr_file) != 0);
 181
 182         hip = HFSPLUS_I(attr_file);
 183
 184         clump_size = hfsplus_calc_btree_clump_size(sb->s_blocksize,
 185                                                     node_size,
 186                                                     sbi->sect_count,
 187                                                     HFSPLUS_ATTR_CNID);
 188
 189         mutex_lock(&hip->extents_lock);
 190         hip->clump_blocks = clump_size >> sbi->alloc_blksz_shift;
 191         mutex_unlock(&hip->extents_lock);
 192
 193         if (sbi->free_blocks <= (hip->clump_blocks << 1)) {
 194                 err = -ENOSPC;
 195                 goto end_attr_file_creation;
 196         }
 197
 198         while (hip->alloc_blocks < hip->clump_blocks) {
 199                 err = hfsplus_file_extend(attr_file, false);
 200                 if (unlikely(err)) {
 201                         pr_err("failed to extend attributes file\n");
 202                         goto end_attr_file_creation;
 203                 }
 204                 hip->phys_size = attr_file->i_size =
 205                         (loff_t)hip->alloc_blocks << sbi->alloc_blksz_shift;
 206                 hip->fs_blocks = hip->alloc_blocks << sbi->fs_shift;
 207                 inode_set_bytes(attr_file, attr_file->i_size);
 208         }
 209
 210         buf = kzalloc(node_size, GFP_NOFS);
 211         if (!buf) {
 212                 pr_err("failed to allocate memory for header node\n");
 213                 err = -ENOMEM;
 214                 goto end_attr_file_creation;
 215         }
 216
 217         hfsplus_init_header_node(attr_file, clump_size, buf, node_size);
 218
 219         mapping = attr_file->i_mapping;
 220
 221         index = 0;
 222         written = 0;
 223         for (; written < node_size; index++, written += PAGE_SIZE) {
 224                 void *kaddr;
 225
 226                 page = read_mapping_page(mapping, index, NULL);
 227                 if (IS_ERR(page)) {
 228                         err = PTR_ERR(page);
 229                         goto failed_header_node_init;
 230                 }
 231
 232                 kaddr = kmap_atomic(page);
 233                 memcpy(kaddr, buf + written,
 234                         min_t(size_t, PAGE_SIZE, node_size - written));
 235                 kunmap_atomic(kaddr);
 236
 237                 set_page_dirty(page);
 238                 put_page(page);
 239         }
 240
 241         hfsplus_mark_inode_dirty(attr_file, HFSPLUS_I_ATTR_DIRTY);
 242
 243         sbi->attr_tree = hfs_btree_open(sb, HFSPLUS_ATTR_CNID);
 244         if (!sbi->attr_tree)
 245                 pr_err("failed to load attributes file\n");
 246
 247 failed_header_node_init:
 248         kfree(buf);
 249
 250 end_attr_file_creation:
 251         iput(attr_file);
 252
 253         if (!err)
 254                 atomic_set(&sbi->attr_tree_state, HFSPLUS_VALID_ATTR_TREE);
 255         else if (err == -ENOSPC)
 256                 atomic_set(&sbi->attr_tree_state, HFSPLUS_EMPTY_ATTR_TREE);
 257         else
 258                 atomic_set(&sbi->attr_tree_state, HFSPLUS_FAILED_ATTR_TREE);
 259
 260         return err;
 261 }
 262
 263 int __hfsplus_setxattr(struct inode *inode, const char *name,
 264                         const void *value, size_t size, int flags)
 265 {
 266         int err = 0;
 267         struct hfs_find_data cat_fd;
 268         hfsplus_cat_entry entry;
 269         u16 cat_entry_flags, cat_entry_type;
 270         u16 folder_finderinfo_len = sizeof(struct DInfo) +
 271                                         sizeof(struct DXInfo);
 272         u16 file_finderinfo_len = sizeof(struct FInfo) +
 273                                         sizeof(struct FXInfo);
 274
 275         if ((!S_ISREG(inode->i_mode) &&
 276                         !S_ISDIR(inode->i_mode)) ||
 277                                 HFSPLUS_IS_RSRC(inode))
 278                 return -EOPNOTSUPP;
 279
 280         if (value == NULL)
 281                 return hfsplus_removexattr(inode, name);
 282
 283         err = hfs_find_init(HFSPLUS_SB(inode->i_sb)->cat_tree, &cat_fd);
 284         if (err) {
 285                 pr_err("can't init xattr find struct\n");
 286                 return err;
 287         }
 288
 289         err = hfsplus_find_cat(inode->i_sb, inode->i_ino, &cat_fd);
 290         if (err) {
 291                 pr_err("catalog searching failed\n");
 292                 goto end_setxattr;
 293         }
 294
 295         if (!strcmp_xattr_finder_info(name)) {
 296                 if (flags & XATTR_CREATE) {
 297                         pr_err("xattr exists yet\n");
 298                         err = -EOPNOTSUPP;
 299                         goto end_setxattr;
 300                 }
 301                 hfs_bnode_read(cat_fd.bnode, &entry, cat_fd.entryoffset,
 302                                         sizeof(hfsplus_cat_entry));
 303                 if (be16_to_cpu(entry.type) == HFSPLUS_FOLDER) {
 304                         if (size == folder_finderinfo_len) {
 305                                 memcpy(&entry.folder.user_info, value,
 306                                                 folder_finderinfo_len);
 307                                 hfs_bnode_write(cat_fd.bnode, &entry,
 308                                         cat_fd.entryoffset,
 309                                         sizeof(struct hfsplus_cat_folder));
 310                                 hfsplus_mark_inode_dirty(inode,
 311                                                 HFSPLUS_I_CAT_DIRTY);
 312                         } else {
 313                                 err = -ERANGE;
 314                                 goto end_setxattr;
 315                         }
 316                 } else if (be16_to_cpu(entry.type) == HFSPLUS_FILE) {
 317                         if (size == file_finderinfo_len) {
 318                                 memcpy(&entry.file.user_info, value,
 319                                                 file_finderinfo_len);
 320                                 hfs_bnode_write(cat_fd.bnode, &entry,
 321                                         cat_fd.entryoffset,
 322                                         sizeof(struct hfsplus_cat_file));
 323                                 hfsplus_mark_inode_dirty(inode,
 324                                                 HFSPLUS_I_CAT_DIRTY);
 325                         } else {
 326                                 err = -ERANGE;
 327                                 goto end_setxattr;
 328                         }
 329                 } else {
 330                         err = -EOPNOTSUPP;
 331                         goto end_setxattr;
 332                 }
 333                 goto end_setxattr;
 334         }
 335
 336         if (!HFSPLUS_SB(inode->i_sb)->attr_tree) {
 337                 err = hfsplus_create_attributes_file(inode->i_sb);
 338                 if (unlikely(err))
 339                         goto end_setxattr;
 340         }
 341
 342         if (hfsplus_attr_exists(inode, name)) {
 343                 if (flags & XATTR_CREATE) {
 344                         pr_err("xattr exists yet\n");
 345                         err = -EOPNOTSUPP;
 346                         goto end_setxattr;
 347                 }
 348                 err = hfsplus_delete_attr(inode, name);
 349                 if (err)
 350                         goto end_setxattr;
 351                 err = hfsplus_create_attr(inode, name, value, size);
 352                 if (err)
 353                         goto end_setxattr;
 354         } else {
 355                 if (flags & XATTR_REPLACE) {
 356                         pr_err("cannot replace xattr\n");
 357                         err = -EOPNOTSUPP;
 358                         goto end_setxattr;
 359                 }
 360                 err = hfsplus_create_attr(inode, name, value, size);
 361                 if (err)
 362                         goto end_setxattr;
 363         }
 364
 365         cat_entry_type = hfs_bnode_read_u16(cat_fd.bnode, cat_fd.entryoffset);
 366         if (cat_entry_type == HFSPLUS_FOLDER) {
 367                 cat_entry_flags = hfs_bnode_read_u16(cat_fd.bnode,
 368                                     cat_fd.entryoffset +
 369                                     offsetof(struct hfsplus_cat_folder, flags));
 370                 cat_entry_flags |= HFSPLUS_XATTR_EXISTS;
 371                 if (!strcmp_xattr_acl(name))
 372                         cat_entry_flags |= HFSPLUS_ACL_EXISTS;
 373                 hfs_bnode_write_u16(cat_fd.bnode, cat_fd.entryoffset +
 374                                 offsetof(struct hfsplus_cat_folder, flags),
 375                                 cat_entry_flags);
 376                 hfsplus_mark_inode_dirty(inode, HFSPLUS_I_CAT_DIRTY);
 377         } else if (cat_entry_type == HFSPLUS_FILE) {
 378                 cat_entry_flags = hfs_bnode_read_u16(cat_fd.bnode,
 379                                     cat_fd.entryoffset +
 380                                     offsetof(struct hfsplus_cat_file, flags));
 381                 cat_entry_flags |= HFSPLUS_XATTR_EXISTS;
 382                 if (!strcmp_xattr_acl(name))
 383                         cat_entry_flags |= HFSPLUS_ACL_EXISTS;
 384                 hfs_bnode_write_u16(cat_fd.bnode, cat_fd.entryoffset +
 385                                     offsetof(struct hfsplus_cat_file, flags),
 386                                     cat_entry_flags);
 387                 hfsplus_mark_inode_dirty(inode, HFSPLUS_I_CAT_DIRTY);
 388         } else {
 389                 pr_err("invalid catalog entry type\n");
 390                 err = -EIO;
 391                 goto end_setxattr;
 392         }
 393
 394 end_setxattr:
 395         hfs_find_exit(&cat_fd);
 396         return err;
 397 }
 398
 399 static int name_len(const char *xattr_name, int xattr_name_len)
 400 {
 401         int len = xattr_name_len + 1;
 402
 403         if (!is_known_namespace(xattr_name))
 404                 len += XATTR_MAC_OSX_PREFIX_LEN;
 405
 406         return len;
 407 }
 408
 409 static int copy_name(char *buffer, const char *xattr_name, int name_len)
 410 {
 411         int len = name_len;
 412         int offset = 0;
 413
 414         if (!is_known_namespace(xattr_name)) {
 415                 strncpy(buffer, XATTR_MAC_OSX_PREFIX, XATTR_MAC_OSX_PREFIX_LEN);
 416                 offset += XATTR_MAC_OSX_PREFIX_LEN;
 417                 len += XATTR_MAC_OSX_PREFIX_LEN;
 418         }
 419
 420         strncpy(buffer + offset, xattr_name, name_len);
 421         memset(buffer + offset + name_len, 0, 1);
 422         len += 1;
 423
 424         return len;
 425 }
 426
 427 int hfsplus_setxattr(struct dentry *dentry, const char *name,
 428                      const void *value, size_t size, int flags,
 429                      const char *prefix, size_t prefixlen)
 430 {
 431         char *xattr_name;
 432         int res;
 433
 434         xattr_name = kmalloc(NLS_MAX_CHARSET_SIZE * HFSPLUS_ATTR_MAX_STRLEN + 1,
 435                 GFP_KERNEL);
 436         if (!xattr_name)
 437                 return -ENOMEM;
 438         strcpy(xattr_name, prefix);
 439         strcpy(xattr_name + prefixlen, name);
 440         res = __hfsplus_setxattr(d_inode(dentry), xattr_name, value, size,
 441                                  flags);
 442         kfree(xattr_name);
 443         return res;
 444 }
 445
 446 static ssize_t hfsplus_getxattr_finder_info(struct inode *inode,
 447                                                 void *value, size_t size)
 448 {
 449         ssize_t res = 0;
 450         struct hfs_find_data fd;
 451         u16 entry_type;
 452         u16 folder_rec_len = sizeof(struct DInfo) + sizeof(struct DXInfo);
 453         u16 file_rec_len = sizeof(struct FInfo) + sizeof(struct FXInfo);
 454         u16 record_len = max(folder_rec_len, file_rec_len);
 455         u8 folder_finder_info[sizeof(struct DInfo) + sizeof(struct DXInfo)];
 456         u8 file_finder_info[sizeof(struct FInfo) + sizeof(struct FXInfo)];
 457
 458         if (size >= record_len) {
 459                 res = hfs_find_init(HFSPLUS_SB(inode->i_sb)->cat_tree, &fd);
 460                 if (res) {
 461                         pr_err("can't init xattr find struct\n");
 462                         return res;
 463                 }
 464                 res = hfsplus_find_cat(inode->i_sb, inode->i_ino, &fd);
 465                 if (res)
 466                         goto end_getxattr_finder_info;
 467                 entry_type = hfs_bnode_read_u16(fd.bnode, fd.entryoffset);
 468
 469                 if (entry_type == HFSPLUS_FOLDER) {
 470                         hfs_bnode_read(fd.bnode, folder_finder_info,
 471                                 fd.entryoffset +
 472                                 offsetof(struct hfsplus_cat_folder, user_info),
 473                                 folder_rec_len);
 474                         memcpy(value, folder_finder_info, folder_rec_len);
 475                         res = folder_rec_len;
 476                 } else if (entry_type == HFSPLUS_FILE) {
 477                         hfs_bnode_read(fd.bnode, file_finder_info,
 478                                 fd.entryoffset +
 479                                 offsetof(struct hfsplus_cat_file, user_info),
 480                                 file_rec_len);
 481                         memcpy(value, file_finder_info, file_rec_len);
 482                         res = file_rec_len;
 483                 } else {
 484                         res = -EOPNOTSUPP;
 485                         goto end_getxattr_finder_info;
 486                 }
 487         } else
 488                 res = size ? -ERANGE : record_len;
 489
 490 end_getxattr_finder_info:
 491         if (size >= record_len)
 492                 hfs_find_exit(&fd);
 493         return res;
 494 }
 495
 496 ssize_t __hfsplus_getxattr(struct inode *inode, const char *name,
 497                          void *value, size_t size)
 498 {
 499         struct hfs_find_data fd;
 500         hfsplus_attr_entry *entry;
 501         __be32 xattr_record_type;
 502         u32 record_type;
 503         u16 record_length = 0;
 504         ssize_t res = 0;
 505
 506         if ((!S_ISREG(inode->i_mode) &&
 507                         !S_ISDIR(inode->i_mode)) ||
 508                                 HFSPLUS_IS_RSRC(inode))
 509                 return -EOPNOTSUPP;
 510
 511         if (!strcmp_xattr_finder_info(name))
 512                 return hfsplus_getxattr_finder_info(inode, value, size);
 513
 514         if (!HFSPLUS_SB(inode->i_sb)->attr_tree)
 515                 return -EOPNOTSUPP;
 516
 517         entry = hfsplus_alloc_attr_entry();
 518         if (!entry) {
 519                 pr_err("can't allocate xattr entry\n");
 520                 return -ENOMEM;
 521         }
 522
 523         res = hfs_find_init(HFSPLUS_SB(inode->i_sb)->attr_tree, &fd);
 524         if (res) {
 525                 pr_err("can't init xattr find struct\n");
 526                 goto failed_getxattr_init;
 527         }
 528
 529         res = hfsplus_find_attr(inode->i_sb, inode->i_ino, name, &fd);
 530         if (res) {
 531                 if (res == -ENOENT)
 532                         res = -ENODATA;
 533                 else
 534                         pr_err("xattr searching failed\n");
 535                 goto out;
 536         }
 537
 538         hfs_bnode_read(fd.bnode, &xattr_record_type,
 539                         fd.entryoffset, sizeof(xattr_record_type));
 540         record_type = be32_to_cpu(xattr_record_type);
 541         if (record_type == HFSPLUS_ATTR_INLINE_DATA) {
 542                 record_length = hfs_bnode_read_u16(fd.bnode,
 543                                 fd.entryoffset +
 544                                 offsetof(struct hfsplus_attr_inline_data,
 545                                 length));
 546                 if (record_length > HFSPLUS_MAX_INLINE_DATA_SIZE) {
 547                         pr_err("invalid xattr record size\n");
 548                         res = -EIO;
 549                         goto out;
 550                 }
 551         } else if (record_type == HFSPLUS_ATTR_FORK_DATA ||
 552                         record_type == HFSPLUS_ATTR_EXTENTS) {
 553                 pr_err("only inline data xattr are supported\n");
 554                 res = -EOPNOTSUPP;
 555                 goto out;
 556         } else {
 557                 pr_err("invalid xattr record\n");
 558                 res = -EIO;
 559                 goto out;
 560         }
 561
 562         if (size) {
 563                 hfs_bnode_read(fd.bnode, entry, fd.entryoffset,
 564                                 offsetof(struct hfsplus_attr_inline_data,
 565                                         raw_bytes) + record_length);
 566         }
 567
 568         if (size >= record_length) {
 569                 memcpy(value, entry->inline_data.raw_bytes, record_length);
 570                 res = record_length;
 571         } else
 572                 res = size ? -ERANGE : record_length;
 573
 574 out:
 575         hfs_find_exit(&fd);
 576
 577 failed_getxattr_init:
 578         hfsplus_destroy_attr_entry(entry);
 579         return res;
 580 }
 581
 582 ssize_t hfsplus_getxattr(struct inode *inode, const char *name,
 583                          void *value, size_t size,
 584                          const char *prefix, size_t prefixlen)
 585 {
 586         int res;
 587         char *xattr_name;
 588
 589         xattr_name = kmalloc(NLS_MAX_CHARSET_SIZE * HFSPLUS_ATTR_MAX_STRLEN + 1,
 590                              GFP_KERNEL);
 591         if (!xattr_name)
 592                 return -ENOMEM;
 593
 594         strcpy(xattr_name, prefix);
 595         strcpy(xattr_name + prefixlen, name);
 596
 597         res = __hfsplus_getxattr(inode, xattr_name, value, size);
 598         kfree(xattr_name);
 599         return res;
 600
 601 }
 602
 603 static inline int can_list(const char *xattr_name)
 604 {
 605         if (!xattr_name)
 606                 return 0;
 607
 608         return strncmp(xattr_name, XATTR_TRUSTED_PREFIX,
 609                         XATTR_TRUSTED_PREFIX_LEN) ||
 610                                 capable(CAP_SYS_ADMIN);
 611 }
 612
 613 static ssize_t hfsplus_listxattr_finder_info(struct dentry *dentry,
 614                                                 char *buffer, size_t size)
 615 {
 616         ssize_t res = 0;
 617         struct inode *inode = d_inode(dentry);
 618         struct hfs_find_data fd;
 619         u16 entry_type;
 620         u8 folder_finder_info[sizeof(struct DInfo) + sizeof(struct DXInfo)];
 621         u8 file_finder_info[sizeof(struct FInfo) + sizeof(struct FXInfo)];
 622         unsigned long len, found_bit;
 623         int xattr_name_len, symbols_count;
 624
 625         res = hfs_find_init(HFSPLUS_SB(inode->i_sb)->cat_tree, &fd);
 626         if (res) {
 627                 pr_err("can't init xattr find struct\n");
 628                 return res;
 629         }
 630
 631         res = hfsplus_find_cat(inode->i_sb, inode->i_ino, &fd);
 632         if (res)
 633                 goto end_listxattr_finder_info;
 634
 635         entry_type = hfs_bnode_read_u16(fd.bnode, fd.entryoffset);
 636         if (entry_type == HFSPLUS_FOLDER) {
 637                 len = sizeof(struct DInfo) + sizeof(struct DXInfo);
 638                 hfs_bnode_read(fd.bnode, folder_finder_info,
 639                                 fd.entryoffset +
 640                                 offsetof(struct hfsplus_cat_folder, user_info),
 641                                 len);
 642                 found_bit = find_first_bit((void *)folder_finder_info, len*8);
 643         } else if (entry_type == HFSPLUS_FILE) {
 644                 len = sizeof(struct FInfo) + sizeof(struct FXInfo);
 645                 hfs_bnode_read(fd.bnode, file_finder_info,
 646                                 fd.entryoffset +
 647                                 offsetof(struct hfsplus_cat_file, user_info),
 648                                 len);
 649                 found_bit = find_first_bit((void *)file_finder_info, len*8);
 650         } else {
 651                 res = -EOPNOTSUPP;
 652                 goto end_listxattr_finder_info;
 653         }
 654
 655         if (found_bit >= (len*8))
 656                 res = 0;
 657         else {
 658                 symbols_count = sizeof(HFSPLUS_XATTR_FINDER_INFO_NAME) - 1;
 659                 xattr_name_len =
 660                         name_len(HFSPLUS_XATTR_FINDER_INFO_NAME, symbols_count);
 661                 if (!buffer || !size) {
 662                         if (can_list(HFSPLUS_XATTR_FINDER_INFO_NAME))
 663                                 res = xattr_name_len;
 664                 } else if (can_list(HFSPLUS_XATTR_FINDER_INFO_NAME)) {
 665                         if (size < xattr_name_len)
 666                                 res = -ERANGE;
 667                         else {
 668                                 res = copy_name(buffer,
 669                                                 HFSPLUS_XATTR_FINDER_INFO_NAME,
 670                                                 symbols_count);
 671                         }
 672                 }
 673         }
 674
 675 end_listxattr_finder_info:
 676         hfs_find_exit(&fd);
 677
 678         return res;
 679 }
 680
 681 ssize_t hfsplus_listxattr(struct dentry *dentry, char *buffer, size_t size)
 682 {
 683         ssize_t err;
 684         ssize_t res = 0;
 685         struct inode *inode = d_inode(dentry);
 686         struct hfs_find_data fd;
 687         u16 key_len = 0;
 688         struct hfsplus_attr_key attr_key;
 689         char *strbuf;
 690         int xattr_name_len;
 691
 692         if ((!S_ISREG(inode->i_mode) &&
 693                         !S_ISDIR(inode->i_mode)) ||
 694                                 HFSPLUS_IS_RSRC(inode))
 695                 return -EOPNOTSUPP;
 696
 697         res = hfsplus_listxattr_finder_info(dentry, buffer, size);
 698         if (res < 0)
 699                 return res;
 700         else if (!HFSPLUS_SB(inode->i_sb)->attr_tree)
 701                 return (res == 0) ? -EOPNOTSUPP : res;
 702
 703         err = hfs_find_init(HFSPLUS_SB(inode->i_sb)->attr_tree, &fd);
 704         if (err) {
 705                 pr_err("can't init xattr find struct\n");
 706                 return err;
 707         }
 708
 709         strbuf = kmalloc(NLS_MAX_CHARSET_SIZE * HFSPLUS_ATTR_MAX_STRLEN +
 710                         XATTR_MAC_OSX_PREFIX_LEN + 1, GFP_KERNEL);
 711         if (!strbuf) {
 712                 res = -ENOMEM;
 713                 goto out;
 714         }
 715
 716         err = hfsplus_find_attr(inode->i_sb, inode->i_ino, NULL, &fd);
 717         if (err) {
 718                 if (err == -ENOENT) {
 719                         if (res == 0)
 720                                 res = -ENODATA;
 721                         goto end_listxattr;
 722                 } else {
 723                         res = err;
 724                         goto end_listxattr;
 725                 }
 726         }
 727
 728         for (;;) {
 729                 key_len = hfs_bnode_read_u16(fd.bnode, fd.keyoffset);
 730                 if (key_len == 0 || key_len > fd.tree->max_key_len) {
 731                         pr_err("invalid xattr key length: %d\n", key_len);
 732                         res = -EIO;
 733                         goto end_listxattr;
 734                 }
 735
 736                 hfs_bnode_read(fd.bnode, &attr_key,
 737                                 fd.keyoffset, key_len + sizeof(key_len));
 738
 739                 if (be32_to_cpu(attr_key.cnid) != inode->i_ino)
 740                         goto end_listxattr;
 741
 742                 xattr_name_len = NLS_MAX_CHARSET_SIZE * HFSPLUS_ATTR_MAX_STRLEN;
 743                 if (hfsplus_uni2asc(inode->i_sb,
 744                         (const struct hfsplus_unistr *)&fd.key->attr.key_name,
 745                                         strbuf, &xattr_name_len)) {
 746                         pr_err("unicode conversion failed\n");
 747                         res = -EIO;
 748                         goto end_listxattr;
 749                 }
 750
 751                 if (!buffer || !size) {
 752                         if (can_list(strbuf))
 753                                 res += name_len(strbuf, xattr_name_len);
 754                 } else if (can_list(strbuf)) {
 755                         if (size < (res + name_len(strbuf, xattr_name_len))) {
 756                                 res = -ERANGE;
 757                                 goto end_listxattr;
 758                         } else
 759                                 res += copy_name(buffer + res,
 760                                                 strbuf, xattr_name_len);
 761                 }
 762
 763                 if (hfs_brec_goto(&fd, 1))
 764                         goto end_listxattr;
 765         }
 766
 767 end_listxattr:
 768         kfree(strbuf);
 769 out:
 770         hfs_find_exit(&fd);
 771         return res;
 772 }
 773
 774 static int hfsplus_removexattr(struct inode *inode, const char *name)
 775 {
 776         int err = 0;
 777         struct hfs_find_data cat_fd;
 778         u16 flags;
 779         u16 cat_entry_type;
 780         int is_xattr_acl_deleted = 0;
 781         int is_all_xattrs_deleted = 0;
 782
 783         if (!HFSPLUS_SB(inode->i_sb)->attr_tree)
 784                 return -EOPNOTSUPP;
 785
 786         if (!strcmp_xattr_finder_info(name))
 787                 return -EOPNOTSUPP;
 788
 789         err = hfs_find_init(HFSPLUS_SB(inode->i_sb)->cat_tree, &cat_fd);
 790         if (err) {
 791                 pr_err("can't init xattr find struct\n");
 792                 return err;
 793         }
 794
 795         err = hfsplus_find_cat(inode->i_sb, inode->i_ino, &cat_fd);
 796         if (err) {
 797                 pr_err("catalog searching failed\n");
 798                 goto end_removexattr;
 799         }
 800
 801         err = hfsplus_delete_attr(inode, name);
 802         if (err)
 803                 goto end_removexattr;
 804
 805         is_xattr_acl_deleted = !strcmp_xattr_acl(name);
 806         is_all_xattrs_deleted = !hfsplus_attr_exists(inode, NULL);
 807
 808         if (!is_xattr_acl_deleted && !is_all_xattrs_deleted)
 809                 goto end_removexattr;
 810
 811         cat_entry_type = hfs_bnode_read_u16(cat_fd.bnode, cat_fd.entryoffset);
 812
 813         if (cat_entry_type == HFSPLUS_FOLDER) {
 814                 flags = hfs_bnode_read_u16(cat_fd.bnode, cat_fd.entryoffset +
 815                                 offsetof(struct hfsplus_cat_folder, flags));
 816                 if (is_xattr_acl_deleted)
 817                         flags &= ~HFSPLUS_ACL_EXISTS;
 818                 if (is_all_xattrs_deleted)
 819                         flags &= ~HFSPLUS_XATTR_EXISTS;
 820                 hfs_bnode_write_u16(cat_fd.bnode, cat_fd.entryoffset +
 821                                 offsetof(struct hfsplus_cat_folder, flags),
 822                                 flags);
 823                 hfsplus_mark_inode_dirty(inode, HFSPLUS_I_CAT_DIRTY);
 824         } else if (cat_entry_type == HFSPLUS_FILE) {
 825                 flags = hfs_bnode_read_u16(cat_fd.bnode, cat_fd.entryoffset +
 826                                 offsetof(struct hfsplus_cat_file, flags));
 827                 if (is_xattr_acl_deleted)
 828                         flags &= ~HFSPLUS_ACL_EXISTS;
 829                 if (is_all_xattrs_deleted)
 830                         flags &= ~HFSPLUS_XATTR_EXISTS;
 831                 hfs_bnode_write_u16(cat_fd.bnode, cat_fd.entryoffset +
 832                                 offsetof(struct hfsplus_cat_file, flags),
 833                                 flags);
 834                 hfsplus_mark_inode_dirty(inode, HFSPLUS_I_CAT_DIRTY);
 835         } else {
 836                 pr_err("invalid catalog entry type\n");
 837                 err = -EIO;
 838                 goto end_removexattr;
 839         }
 840
 841 end_removexattr:
 842         hfs_find_exit(&cat_fd);
 843         return err;
 844 }
 845
 846 static int hfsplus_osx_getxattr(const struct xattr_handler *handler,
 847                                 struct dentry *unused, struct inode *inode,
 848                                 const char *name, void *buffer, size_t size)
 849 {
 850         /*
 851          * Don't allow retrieving properly prefixed attributes
 852          * by prepending them with "osx."
 853          */
 854         if (is_known_namespace(name))
 855                 return -EOPNOTSUPP;
 856
 857         /*
 858          * osx is the namespace we use to indicate an unprefixed
 859          * attribute on the filesystem (like the ones that OS X
 860          * creates), so we pass the name through unmodified (after
 861          * ensuring it doesn't conflict with another namespace).
 862          */
 863         return __hfsplus_getxattr(inode, name, buffer, size);
 864 }
 865
 866 static int hfsplus_osx_setxattr(const struct xattr_handler *handler,
 867                                 struct dentry *dentry, const char *name,
 868                                 const void *buffer, size_t size, int flags)
 869 {
 870         /*
 871          * Don't allow setting properly prefixed attributes
 872          * by prepending them with "osx."
 873          */
 874         if (is_known_namespace(name))
 875                 return -EOPNOTSUPP;
 876
 877         /*
 878          * osx is the namespace we use to indicate an unprefixed
 879          * attribute on the filesystem (like the ones that OS X
 880          * creates), so we pass the name through unmodified (after
 881          * ensuring it doesn't conflict with another namespace).
 882          */
 883         return __hfsplus_setxattr(d_inode(dentry), name, buffer, size, flags);
 884 }
 885
 886 const struct xattr_handler hfsplus_xattr_osx_handler = {
 887         .prefix = XATTR_MAC_OSX_PREFIX,
 888         .get    = hfsplus_osx_getxattr,
 889         .set    = hfsplus_osx_setxattr,
 890 };