fs/reiser4/plugin/object.c

   1 /* Copyright 2001, 2002, 2003 by Hans Reiser, licensing governed by
   2  * reiser4/README */
   3
   4 /*
   5  * Examples of object plugins: file, directory, symlink, special file.
   6  *
   7  * Plugins associated with inode:
   8  *
   9  * Plugin of inode is plugin referenced by plugin-id field of on-disk
  10  * stat-data. How we store this plugin in in-core inode is not
  11  * important. Currently pointers are used, another variant is to store offsets
  12  * and do array lookup on each access.
  13  *
  14  * Now, each inode has one selected plugin: object plugin that
  15  * determines what type of file this object is: directory, regular etc.
  16  *
  17  * This main plugin can use other plugins that are thus subordinated to
  18  * it. Directory instance of object plugin uses hash; regular file
  19  * instance uses tail policy plugin.
  20  *
  21  * Object plugin is either taken from id in stat-data or guessed from
  22  * i_mode bits. Once it is established we ask it to install its
  23  * subordinate plugins, by looking again in stat-data or inheriting them
  24  * from parent.
  25  *
  26  * How new inode is initialized during ->read_inode():
  27  * 1 read stat-data and initialize inode fields: i_size, i_mode,
  28  *   i_generation, capabilities etc.
  29  * 2 read plugin id from stat data or try to guess plugin id
  30  *   from inode->i_mode bits if plugin id is missing.
  31  * 3 Call ->init_inode() method of stat-data plugin to initialise inode fields.
  32  *
  33  * NIKITA-FIXME-HANS: can you say a little about 1 being done before 3?  What
  34  * if stat data does contain i_size, etc., due to it being an unusual plugin?
  35  *
  36  * 4 Call ->activate() method of object's plugin. Plugin is either read from
  37  *    from stat-data or guessed from mode bits
  38  * 5 Call ->inherit() method of object plugin to inherit as yet un initialized
  39  *    plugins from parent.
  40  *
  41  * Easy induction proves that on last step all plugins of inode would be
  42  * initialized.
  43  *
  44  * When creating new object:
  45  * 1 obtain object plugin id (see next period)
  46  * NIKITA-FIXME-HANS: period?
  47  * 2 ->install() this plugin
  48  * 3 ->inherit() the rest from the parent
  49  *
  50  * We need some examples of creating an object with default and non-default
  51  * plugin ids.  Nikita, please create them.
  52  */
  53
  54 #include "../inode.h"
  55
  56 static int _bugop(void)
  57 {
  58         BUG_ON(1);
  59         return 0;
  60 }
  61
  62 #define bugop ((void *)_bugop)
  63
  64 static int _dummyop(void)
  65 {
  66         return 0;
  67 }
  68
  69 #define dummyop ((void *)_dummyop)
  70
  71 static int change_file(struct inode *inode,
  72                        reiser4_plugin * plugin,
  73                        pset_member memb)
  74 {
  75         /* cannot change object plugin of already existing object */
  76         if (memb == PSET_FILE)
  77                 return RETERR(-EINVAL);
  78
  79         /* Change PSET_CREATE */
  80         return aset_set_unsafe(&reiser4_inode_data(inode)->pset, memb, plugin);
  81 }
  82
  83 static reiser4_plugin_ops file_plugin_ops = {
  84         .change = change_file
  85 };
  86
  87 /*
  88  * Definitions of object plugins.
  89  */
  90
  91 file_plugin file_plugins[LAST_FILE_PLUGIN_ID] = {
  92         [UNIX_FILE_PLUGIN_ID] = {
  93                 .h = {
  94                         .type_id = REISER4_FILE_PLUGIN_TYPE,
  95                         .id = UNIX_FILE_PLUGIN_ID,
  96                         .groups = (1 << REISER4_REGULAR_FILE),
  97                         .pops = &file_plugin_ops,
  98                         .label = "reg",
  99                         .desc = "regular file",
 100                         .linkage = {NULL, NULL},
 101                 },
 102                 .inode_ops = {
 103                         .permission = reiser4_permission_common,
 104                         .setattr = setattr_unix_file,
 105                         .getattr = reiser4_getattr_common
 106                 },
 107                 .file_ops = {
 108                         .llseek = generic_file_llseek,
 109                         .read = read_unix_file,
 110                         .write = write_unix_file,
 111                         .aio_read = generic_file_aio_read,
 112                         .ioctl = ioctl_unix_file,
 113                         .mmap = mmap_unix_file,
 114                         .open = open_unix_file,
 115                         .release = release_unix_file,
 116                         .fsync = sync_unix_file,
 117                 },
 118                 .as_ops = {
 119                         .writepage = reiser4_writepage,
 120                         .readpage = readpage_unix_file,
 121                         .sync_page = block_sync_page,
 122                         .writepages = writepages_unix_file,
 123                         .set_page_dirty = reiser4_set_page_dirty,
 124                         .readpages = readpages_unix_file,
 125                         .prepare_write = prepare_write_unix_file,
 126                         .commit_write = commit_write_unix_file,
 127                         .bmap = bmap_unix_file,
 128                         .invalidatepage = reiser4_invalidatepage,
 129                         .releasepage = reiser4_releasepage
 130                 },
 131                 .write_sd_by_inode = write_sd_by_inode_common,
 132                 .flow_by_inode = flow_by_inode_unix_file,
 133                 .key_by_inode = key_by_inode_and_offset_common,
 134                 .set_plug_in_inode = set_plug_in_inode_common,
 135                 .adjust_to_parent = adjust_to_parent_common,
 136                 .create_object = reiser4_create_object_common,
 137                 .delete_object = delete_object_unix_file,
 138                 .add_link = reiser4_add_link_common,
 139                 .rem_link = reiser4_rem_link_common,
 140                 .owns_item = owns_item_unix_file,
 141                 .can_add_link = can_add_link_common,
 142                 .detach = dummyop,
 143                 .bind = dummyop,
 144                 .safelink = safelink_common,
 145                 .estimate = {
 146                         .create = estimate_create_common,
 147                         .update = estimate_update_common,
 148                         .unlink = estimate_unlink_common
 149                 },
 150                 .init_inode_data = init_inode_data_unix_file,
 151                 .cut_tree_worker = cut_tree_worker_common,
 152                 .wire = {
 153                         .write = wire_write_common,
 154                         .read = wire_read_common,
 155                         .get = wire_get_common,
 156                         .size = wire_size_common,
 157                         .done = wire_done_common
 158                 }
 159         },
 160         [DIRECTORY_FILE_PLUGIN_ID] = {
 161                 .h = {
 162                         .type_id = REISER4_FILE_PLUGIN_TYPE,
 163                         .id = DIRECTORY_FILE_PLUGIN_ID,
 164                         .groups = (1 << REISER4_DIRECTORY_FILE),
 165                         .pops = &file_plugin_ops,
 166                         .label = "dir",
 167                         .desc = "directory",
 168                         .linkage = {NULL, NULL}
 169                 },
 170                 .inode_ops = {.create = NULL},
 171                 .file_ops = {.owner = NULL},
 172                 .as_ops = {.writepage = NULL},
 173
 174                 .write_sd_by_inode = write_sd_by_inode_common,
 175                 .flow_by_inode = bugop,
 176                 .key_by_inode = bugop,
 177                 .set_plug_in_inode = set_plug_in_inode_common,
 178                 .adjust_to_parent = adjust_to_parent_common_dir,
 179                 .create_object = reiser4_create_object_common,
 180                 .delete_object = reiser4_delete_dir_common,
 181                 .add_link = reiser4_add_link_common,
 182                 .rem_link = rem_link_common_dir,
 183                 .owns_item = owns_item_common_dir,
 184                 .can_add_link = can_add_link_common,
 185                 .can_rem_link = can_rem_link_common_dir,
 186                 .detach = reiser4_detach_common_dir,
 187                 .bind = reiser4_bind_common_dir,
 188                 .safelink = safelink_common,
 189                 .estimate = {
 190                         .create = estimate_create_common_dir,
 191                         .update = estimate_update_common,
 192                         .unlink = estimate_unlink_common_dir
 193                 },
 194                 .wire = {
 195                         .write = wire_write_common,
 196                         .read = wire_read_common,
 197                         .get = wire_get_common,
 198                         .size = wire_size_common,
 199                         .done = wire_done_common
 200                 },
 201                 .init_inode_data = init_inode_ordering,
 202                 .cut_tree_worker = cut_tree_worker_common,
 203         },
 204         [SYMLINK_FILE_PLUGIN_ID] = {
 205                 .h = {
 206                         .type_id = REISER4_FILE_PLUGIN_TYPE,
 207                         .id = SYMLINK_FILE_PLUGIN_ID,
 208                         .groups = (1 << REISER4_SYMLINK_FILE),
 209                         .pops = &file_plugin_ops,
 210                         .label = "symlink",
 211                         .desc = "symbolic link",
 212                         .linkage = {NULL,NULL}
 213                 },
 214                 .inode_ops = {
 215                         .readlink = generic_readlink,
 216                         .follow_link = reiser4_follow_link_common,
 217                         .permission = reiser4_permission_common,
 218                         .setattr = reiser4_setattr_common,
 219                         .getattr = reiser4_getattr_common
 220                 },
 221                 /* inode->i_fop of symlink is initialized by NULL in setup_inode_ops */
 222                 .file_ops = {.owner = NULL},
 223                 .as_ops = {.writepage = NULL},
 224
 225                 .write_sd_by_inode = write_sd_by_inode_common,
 226                 .set_plug_in_inode = set_plug_in_inode_common,
 227                 .adjust_to_parent = adjust_to_parent_common,
 228                 .create_object = reiser4_create_symlink,
 229                 .delete_object = reiser4_delete_object_common,
 230                 .add_link = reiser4_add_link_common,
 231                 .rem_link = reiser4_rem_link_common,
 232                 .can_add_link = can_add_link_common,
 233                 .detach = dummyop,
 234                 .bind = dummyop,
 235                 .safelink = safelink_common,
 236                 .estimate = {
 237                         .create = estimate_create_common,
 238                         .update = estimate_update_common,
 239                         .unlink = estimate_unlink_common
 240                 },
 241                 .init_inode_data = init_inode_ordering,
 242                 .cut_tree_worker = cut_tree_worker_common,
 243                 .destroy_inode = destroy_inode_symlink,
 244                 .wire = {
 245                         .write = wire_write_common,
 246                         .read = wire_read_common,
 247                         .get = wire_get_common,
 248                         .size = wire_size_common,
 249                         .done = wire_done_common
 250                 }
 251         },
 252         [SPECIAL_FILE_PLUGIN_ID] = {
 253                 .h = {
 254                         .type_id = REISER4_FILE_PLUGIN_TYPE,
 255                         .id = SPECIAL_FILE_PLUGIN_ID,
 256                         .groups = (1 << REISER4_SPECIAL_FILE),
 257                         .pops = &file_plugin_ops,
 258                         .label = "special",
 259                         .desc =
 260                         "special: fifo, device or socket",
 261                         .linkage = {NULL, NULL}
 262                 },
 263                 .inode_ops = {
 264                         .permission = reiser4_permission_common,
 265                         .setattr = reiser4_setattr_common,
 266                         .getattr = reiser4_getattr_common
 267                 },
 268                 /* file_ops of special files (sockets, block, char, fifo) are
 269                    initialized by init_special_inode. */
 270                 .file_ops = {.owner = NULL},
 271                 .as_ops = {.writepage = NULL},
 272
 273                 .write_sd_by_inode = write_sd_by_inode_common,
 274                 .set_plug_in_inode = set_plug_in_inode_common,
 275                 .adjust_to_parent = adjust_to_parent_common,
 276                 .create_object = reiser4_create_object_common,
 277                 .delete_object = reiser4_delete_object_common,
 278                 .add_link = reiser4_add_link_common,
 279                 .rem_link = reiser4_rem_link_common,
 280                 .owns_item = owns_item_common,
 281                 .can_add_link = can_add_link_common,
 282                 .detach = dummyop,
 283                 .bind = dummyop,
 284                 .safelink = safelink_common,
 285                 .estimate = {
 286                         .create = estimate_create_common,
 287                         .update = estimate_update_common,
 288                         .unlink = estimate_unlink_common
 289                 },
 290                 .init_inode_data = init_inode_ordering,
 291                 .cut_tree_worker = cut_tree_worker_common,
 292                 .wire = {
 293                         .write = wire_write_common,
 294                         .read = wire_read_common,
 295                         .get = wire_get_common,
 296                         .size = wire_size_common,
 297                         .done = wire_done_common
 298                 }
 299         },
 300         [CRYPTCOMPRESS_FILE_PLUGIN_ID] = {
 301                 .h = {
 302                         .type_id = REISER4_FILE_PLUGIN_TYPE,
 303                         .id = CRYPTCOMPRESS_FILE_PLUGIN_ID,
 304                         .groups = (1 << REISER4_REGULAR_FILE),
 305                         .pops = &file_plugin_ops,
 306                         .label = "cryptcompress",
 307                         .desc = "cryptcompress file",
 308                         .linkage = {NULL, NULL}
 309                 },
 310                 .inode_ops = {
 311                         .permission = reiser4_permission_common,
 312                         .setattr = prot_setattr_cryptcompress,
 313                         .getattr = reiser4_getattr_common
 314                 },
 315                 .file_ops = {
 316                         .llseek = generic_file_llseek,
 317                         .read = prot_read_cryptcompress,
 318                         .write = prot_write_cryptcompress,
 319                         .aio_read = generic_file_aio_read,
 320                         .mmap = prot_mmap_cryptcompress,
 321                         .release = prot_release_cryptcompress,
 322                         .fsync = reiser4_sync_common,
 323                 },
 324                 .as_ops = {
 325                         .writepage = reiser4_writepage,
 326                         .readpage = readpage_cryptcompress,
 327                         .sync_page = block_sync_page,
 328                         .writepages = writepages_cryptcompress,
 329                         .set_page_dirty = reiser4_set_page_dirty,
 330                         .readpages = readpages_cryptcompress,
 331                         .prepare_write = prepare_write_common,
 332                         .invalidatepage = reiser4_invalidatepage,
 333                         .releasepage = reiser4_releasepage
 334                 },
 335                 .write_sd_by_inode = write_sd_by_inode_common,
 336                 .flow_by_inode = flow_by_inode_cryptcompress,
 337                 .key_by_inode = key_by_inode_cryptcompress,
 338                 .set_plug_in_inode = set_plug_in_inode_common,
 339                 .adjust_to_parent = adjust_to_parent_cryptcompress,
 340                 .create_object = create_cryptcompress,
 341                 .open_object = open_object_cryptcompress,
 342                 .delete_object = delete_object_cryptcompress,
 343                 .add_link = reiser4_add_link_common,
 344                 .rem_link = reiser4_rem_link_common,
 345                 .owns_item = owns_item_common,
 346                 .can_add_link = can_add_link_common,
 347                 .detach = dummyop,
 348                 .bind = dummyop,
 349                 .safelink = safelink_common,
 350                 .estimate = {
 351                         .create = estimate_create_common,
 352                         .update = estimate_update_common,
 353                         .unlink = estimate_unlink_common
 354                 },
 355                 .init_inode_data = init_inode_data_cryptcompress,
 356                 .cut_tree_worker = cut_tree_worker_cryptcompress,
 357                 .destroy_inode = destroy_inode_cryptcompress,
 358                 .wire = {
 359                         .write = wire_write_common,
 360                         .read = wire_read_common,
 361                         .get = wire_get_common,
 362                         .size = wire_size_common,
 363                         .done = wire_done_common
 364                 }
 365         }
 366 };
 367
 368 static int change_dir(struct inode *inode,
 369                       reiser4_plugin * plugin,
 370                       pset_member memb)
 371 {
 372         /* cannot change dir plugin of already existing object */
 373         return RETERR(-EINVAL);
 374 }
 375
 376 static reiser4_plugin_ops dir_plugin_ops = {
 377         .change = change_dir
 378 };
 379
 380 /*
 381  * definition of directory plugins
 382  */
 383
 384 dir_plugin dir_plugins[LAST_DIR_ID] = {
 385         /* standard hashed directory plugin */
 386         [HASHED_DIR_PLUGIN_ID] = {
 387                 .h = {
 388                         .type_id = REISER4_DIR_PLUGIN_TYPE,
 389                         .id = HASHED_DIR_PLUGIN_ID,
 390                         .pops = &dir_plugin_ops,
 391                         .label = "dir",
 392                         .desc = "hashed directory",
 393                         .linkage = {NULL, NULL}
 394                 },
 395                 .inode_ops = {
 396                         .create = reiser4_create_common,
 397                         .lookup = reiser4_lookup_common,
 398                         .link = reiser4_link_common,
 399                         .unlink = reiser4_unlink_common,
 400                         .symlink = reiser4_symlink_common,
 401                         .mkdir = reiser4_mkdir_common,
 402                         .rmdir = reiser4_unlink_common,
 403                         .mknod = reiser4_mknod_common,
 404                         .rename = reiser4_rename_common,
 405                         .permission = reiser4_permission_common,
 406                         .setattr = reiser4_setattr_common,
 407                         .getattr = reiser4_getattr_common
 408                 },
 409                 .file_ops = {
 410                         .llseek = reiser4_llseek_dir_common,
 411                         .read = generic_read_dir,
 412                         .readdir = reiser4_readdir_common,
 413                         .release = reiser4_release_dir_common,
 414                         .fsync = reiser4_sync_common
 415                 },
 416                 .as_ops = {
 417                         .writepage = bugop,
 418                         .sync_page = bugop,
 419                         .writepages = dummyop,
 420                         .set_page_dirty = bugop,
 421                         .readpages = bugop,
 422                         .prepare_write = bugop,
 423                         .commit_write = bugop,
 424                         .bmap = bugop,
 425                         .invalidatepage = bugop,
 426                         .releasepage = bugop
 427                 },
 428                 .get_parent = get_parent_common,
 429                 .is_name_acceptable = is_name_acceptable_common,
 430                 .build_entry_key = build_entry_key_hashed,
 431                 .build_readdir_key = build_readdir_key_common,
 432                 .add_entry = reiser4_add_entry_common,
 433                 .rem_entry = reiser4_rem_entry_common,
 434                 .init = reiser4_dir_init_common,
 435                 .done = reiser4_dir_done_common,
 436                 .attach = reiser4_attach_common,
 437                 .detach = reiser4_detach_common,
 438                 .estimate = {
 439                         .add_entry = estimate_add_entry_common,
 440                         .rem_entry = estimate_rem_entry_common,
 441                         .unlink = dir_estimate_unlink_common
 442                 }
 443         },
 444         /* hashed directory for which seekdir/telldir are guaranteed to
 445          * work. Brain-damage. */
 446         [SEEKABLE_HASHED_DIR_PLUGIN_ID] = {
 447                 .h = {
 448                         .type_id = REISER4_DIR_PLUGIN_TYPE,
 449                         .id = SEEKABLE_HASHED_DIR_PLUGIN_ID,
 450                         .pops = &dir_plugin_ops,
 451                         .label = "dir32",
 452                         .desc = "directory hashed with 31 bit hash",
 453                         .linkage = {NULL, NULL}
 454                 },
 455                 .inode_ops = {
 456                         .create = reiser4_create_common,
 457                         .lookup = reiser4_lookup_common,
 458                         .link = reiser4_link_common,
 459                         .unlink = reiser4_unlink_common,
 460                         .symlink = reiser4_symlink_common,
 461                         .mkdir = reiser4_mkdir_common,
 462                         .rmdir = reiser4_unlink_common,
 463                         .mknod = reiser4_mknod_common,
 464                         .rename = reiser4_rename_common,
 465                         .permission = reiser4_permission_common,
 466                         .setattr = reiser4_setattr_common,
 467                         .getattr = reiser4_getattr_common
 468                 },
 469                 .file_ops = {
 470                         .llseek = reiser4_llseek_dir_common,
 471                         .read = generic_read_dir,
 472                         .readdir = reiser4_readdir_common,
 473                         .release = reiser4_release_dir_common,
 474                         .fsync = reiser4_sync_common
 475                 },
 476                 .as_ops = {
 477                         .writepage = bugop,
 478                         .sync_page = bugop,
 479                         .writepages = dummyop,
 480                         .set_page_dirty = bugop,
 481                         .readpages = bugop,
 482                         .prepare_write = bugop,
 483                         .commit_write = bugop,
 484                         .bmap = bugop,
 485                         .invalidatepage = bugop,
 486                         .releasepage = bugop
 487                 },
 488                 .get_parent = get_parent_common,
 489                 .is_name_acceptable = is_name_acceptable_common,
 490                 .build_entry_key = build_entry_key_seekable,
 491                 .build_readdir_key = build_readdir_key_common,
 492                 .add_entry = reiser4_add_entry_common,
 493                 .rem_entry = reiser4_rem_entry_common,
 494                 .init = reiser4_dir_init_common,
 495                 .done = reiser4_dir_done_common,
 496                 .attach = reiser4_attach_common,
 497                 .detach = reiser4_detach_common,
 498                 .estimate = {
 499                         .add_entry = estimate_add_entry_common,
 500                         .rem_entry = estimate_rem_entry_common,
 501                         .unlink = dir_estimate_unlink_common
 502                 }
 503         }
 504 };
 505
 506 /* Make Linus happy.
 507    Local variables:
 508    c-indentation-style: "K&R"
 509    mode-name: "LC"
 510    c-basic-offset: 8
 511    tab-width: 8
 512    fill-column: 120
 513    End:
 514 */