1 /* 2 * linux/fs/affs/inode.c 3 * 4 * (c) 1996 Hans-Joachim Widmaier - Rewritten 5 * 6 * (C) 1993 Ray Burr - Modified for Amiga FFS filesystem. 7 * 8 * (C) 1992 Eric Youngdale Modified for ISO 9660 filesystem. 9 * 10 * (C) 1991 Linus Torvalds - minix filesystem 11 */ 12 13 #include <linux/module.h> 14 #include <linux/init.h> 15 #include <linux/statfs.h> 16 #include <linux/parser.h> 17 #include <linux/magic.h> 18 #include <linux/sched.h> 19 #include <linux/slab.h> 20 #include <linux/writeback.h> 21 #include <linux/blkdev.h> 22 #include "affs.h" 23 24 static int affs_statfs(struct dentry *dentry, struct kstatfs *buf); 25 static int affs_remount (struct super_block *sb, int *flags, char *data); 26 27 static void 28 affs_commit_super(struct super_block *sb, int wait) 29 { 30 struct affs_sb_info *sbi = AFFS_SB(sb); 31 struct buffer_head *bh = sbi->s_root_bh; 32 struct affs_root_tail *tail = AFFS_ROOT_TAIL(sb, bh); 33 34 lock_buffer(bh); 35 secs_to_datestamp(get_seconds(), &tail->disk_change); 36 affs_fix_checksum(sb, bh); 37 unlock_buffer(bh); 38 39 mark_buffer_dirty(bh); 40 if (wait) 41 sync_dirty_buffer(bh); 42 } 43 44 static void 45 affs_put_super(struct super_block *sb) 46 { 47 struct affs_sb_info *sbi = AFFS_SB(sb); 48 pr_debug("%s()\n", __func__); 49 50 cancel_delayed_work_sync(&sbi->sb_work); 51 } 52 53 static int 54 affs_sync_fs(struct super_block *sb, int wait) 55 { 56 affs_commit_super(sb, wait); 57 return 0; 58 } 59 60 static void flush_superblock(struct work_struct *work) 61 { 62 struct affs_sb_info *sbi; 63 struct super_block *sb; 64 65 sbi = container_of(work, struct affs_sb_info, sb_work.work); 66 sb = sbi->sb; 67 68 spin_lock(&sbi->work_lock); 69 sbi->work_queued = 0; 70 spin_unlock(&sbi->work_lock); 71 72 affs_commit_super(sb, 1); 73 } 74 75 void affs_mark_sb_dirty(struct super_block *sb) 76 { 77 struct affs_sb_info *sbi = AFFS_SB(sb); 78 unsigned long delay; 79 80 if (sb->s_flags & MS_RDONLY) 81 return; 82 83 spin_lock(&sbi->work_lock); 84 if (!sbi->work_queued) { 85 delay = msecs_to_jiffies(dirty_writeback_interval * 10); 86 queue_delayed_work(system_long_wq, &sbi->sb_work, delay); 87 sbi->work_queued = 1; 88 } 89 spin_unlock(&sbi->work_lock); 90 } 91 92 static struct kmem_cache * affs_inode_cachep; 93 94 static struct inode *affs_alloc_inode(struct super_block *sb) 95 { 96 struct affs_inode_info *i; 97 98 i = kmem_cache_alloc(affs_inode_cachep, GFP_KERNEL); 99 if (!i) 100 return NULL; 101 102 i->vfs_inode.i_version = 1; 103 i->i_lc = NULL; 104 i->i_ext_bh = NULL; 105 i->i_pa_cnt = 0; 106 107 return &i->vfs_inode; 108 } 109 110 static void affs_i_callback(struct rcu_head *head) 111 { 112 struct inode *inode = container_of(head, struct inode, i_rcu); 113 kmem_cache_free(affs_inode_cachep, AFFS_I(inode)); 114 } 115 116 static void affs_destroy_inode(struct inode *inode) 117 { 118 call_rcu(&inode->i_rcu, affs_i_callback); 119 } 120 121 static void init_once(void *foo) 122 { 123 struct affs_inode_info *ei = (struct affs_inode_info *) foo; 124 125 sema_init(&ei->i_link_lock, 1); 126 sema_init(&ei->i_ext_lock, 1); 127 inode_init_once(&ei->vfs_inode); 128 } 129 130 static int __init init_inodecache(void) 131 { 132 affs_inode_cachep = kmem_cache_create("affs_inode_cache", 133 sizeof(struct affs_inode_info), 134 0, (SLAB_RECLAIM_ACCOUNT| 135 SLAB_MEM_SPREAD), 136 init_once); 137 if (affs_inode_cachep == NULL) 138 return -ENOMEM; 139 return 0; 140 } 141 142 static void destroy_inodecache(void) 143 { 144 /* 145 * Make sure all delayed rcu free inodes are flushed before we 146 * destroy cache. 147 */ 148 rcu_barrier(); 149 kmem_cache_destroy(affs_inode_cachep); 150 } 151 152 static const struct super_operations affs_sops = { 153 .alloc_inode = affs_alloc_inode, 154 .destroy_inode = affs_destroy_inode, 155 .write_inode = affs_write_inode, 156 .evict_inode = affs_evict_inode, 157 .put_super = affs_put_super, 158 .sync_fs = affs_sync_fs, 159 .statfs = affs_statfs, 160 .remount_fs = affs_remount, 161 .show_options = generic_show_options, 162 }; 163 164 enum { 165 Opt_bs, Opt_mode, Opt_mufs, Opt_notruncate, Opt_prefix, Opt_protect, 166 Opt_reserved, Opt_root, Opt_setgid, Opt_setuid, 167 Opt_verbose, Opt_volume, Opt_ignore, Opt_err, 168 }; 169 170 static const match_table_t tokens = { 171 {Opt_bs, "bs=%u"}, 172 {Opt_mode, "mode=%o"}, 173 {Opt_mufs, "mufs"}, 174 {Opt_notruncate, "nofilenametruncate"}, 175 {Opt_prefix, "prefix=%s"}, 176 {Opt_protect, "protect"}, 177 {Opt_reserved, "reserved=%u"}, 178 {Opt_root, "root=%u"}, 179 {Opt_setgid, "setgid=%u"}, 180 {Opt_setuid, "setuid=%u"}, 181 {Opt_verbose, "verbose"}, 182 {Opt_volume, "volume=%s"}, 183 {Opt_ignore, "grpquota"}, 184 {Opt_ignore, "noquota"}, 185 {Opt_ignore, "quota"}, 186 {Opt_ignore, "usrquota"}, 187 {Opt_err, NULL}, 188 }; 189 190 static int 191 parse_options(char *options, kuid_t *uid, kgid_t *gid, int *mode, int *reserved, s32 *root, 192 int *blocksize, char **prefix, char *volume, unsigned long *mount_opts) 193 { 194 char *p; 195 substring_t args[MAX_OPT_ARGS]; 196 197 /* Fill in defaults */ 198 199 *uid = current_uid(); 200 *gid = current_gid(); 201 *reserved = 2; 202 *root = -1; 203 *blocksize = -1; 204 volume[0] = ':'; 205 volume[1] = 0; 206 *mount_opts = 0; 207 if (!options) 208 return 1; 209 210 while ((p = strsep(&options, ",")) != NULL) { 211 int token, n, option; 212 if (!*p) 213 continue; 214 215 token = match_token(p, tokens, args); 216 switch (token) { 217 case Opt_bs: 218 if (match_int(&args[0], &n)) 219 return 0; 220 if (n != 512 && n != 1024 && n != 2048 221 && n != 4096) { 222 pr_warn("Invalid blocksize (512, 1024, 2048, 4096 allowed)\n"); 223 return 0; 224 } 225 *blocksize = n; 226 break; 227 case Opt_mode: 228 if (match_octal(&args[0], &option)) 229 return 0; 230 *mode = option & 0777; 231 affs_set_opt(*mount_opts, SF_SETMODE); 232 break; 233 case Opt_mufs: 234 affs_set_opt(*mount_opts, SF_MUFS); 235 break; 236 case Opt_notruncate: 237 affs_set_opt(*mount_opts, SF_NO_TRUNCATE); 238 break; 239 case Opt_prefix: 240 *prefix = match_strdup(&args[0]); 241 if (!*prefix) 242 return 0; 243 affs_set_opt(*mount_opts, SF_PREFIX); 244 break; 245 case Opt_protect: 246 affs_set_opt(*mount_opts, SF_IMMUTABLE); 247 break; 248 case Opt_reserved: 249 if (match_int(&args[0], reserved)) 250 return 0; 251 break; 252 case Opt_root: 253 if (match_int(&args[0], root)) 254 return 0; 255 break; 256 case Opt_setgid: 257 if (match_int(&args[0], &option)) 258 return 0; 259 *gid = make_kgid(current_user_ns(), option); 260 if (!gid_valid(*gid)) 261 return 0; 262 affs_set_opt(*mount_opts, SF_SETGID); 263 break; 264 case Opt_setuid: 265 if (match_int(&args[0], &option)) 266 return 0; 267 *uid = make_kuid(current_user_ns(), option); 268 if (!uid_valid(*uid)) 269 return 0; 270 affs_set_opt(*mount_opts, SF_SETUID); 271 break; 272 case Opt_verbose: 273 affs_set_opt(*mount_opts, SF_VERBOSE); 274 break; 275 case Opt_volume: { 276 char *vol = match_strdup(&args[0]); 277 if (!vol) 278 return 0; 279 strlcpy(volume, vol, 32); 280 kfree(vol); 281 break; 282 } 283 case Opt_ignore: 284 /* Silently ignore the quota options */ 285 break; 286 default: 287 pr_warn("Unrecognized mount option \"%s\" or missing value\n", 288 p); 289 return 0; 290 } 291 } 292 return 1; 293 } 294 295 /* This function definitely needs to be split up. Some fine day I'll 296 * hopefully have the guts to do so. Until then: sorry for the mess. 297 */ 298 299 static int affs_fill_super(struct super_block *sb, void *data, int silent) 300 { 301 struct affs_sb_info *sbi; 302 struct buffer_head *root_bh = NULL; 303 struct buffer_head *boot_bh; 304 struct inode *root_inode = NULL; 305 s32 root_block; 306 int size, blocksize; 307 u32 chksum; 308 int num_bm; 309 int i, j; 310 kuid_t uid; 311 kgid_t gid; 312 int reserved; 313 unsigned long mount_flags; 314 int tmp_flags; /* fix remount prototype... */ 315 u8 sig[4]; 316 int ret; 317 318 save_mount_options(sb, data); 319 320 pr_debug("read_super(%s)\n", data ? (const char *)data : "no options"); 321 322 sb->s_magic = AFFS_SUPER_MAGIC; 323 sb->s_op = &affs_sops; 324 sb->s_flags |= MS_NODIRATIME; 325 326 sbi = kzalloc(sizeof(struct affs_sb_info), GFP_KERNEL); 327 if (!sbi) 328 return -ENOMEM; 329 330 sb->s_fs_info = sbi; 331 sbi->sb = sb; 332 mutex_init(&sbi->s_bmlock); 333 spin_lock_init(&sbi->symlink_lock); 334 spin_lock_init(&sbi->work_lock); 335 INIT_DELAYED_WORK(&sbi->sb_work, flush_superblock); 336 337 if (!parse_options(data,&uid,&gid,&i,&reserved,&root_block, 338 &blocksize,&sbi->s_prefix, 339 sbi->s_volume, &mount_flags)) { 340 pr_err("Error parsing options\n"); 341 return -EINVAL; 342 } 343 /* N.B. after this point s_prefix must be released */ 344 345 sbi->s_flags = mount_flags; 346 sbi->s_mode = i; 347 sbi->s_uid = uid; 348 sbi->s_gid = gid; 349 sbi->s_reserved= reserved; 350 351 /* Get the size of the device in 512-byte blocks. 352 * If we later see that the partition uses bigger 353 * blocks, we will have to change it. 354 */ 355 356 size = i_size_read(sb->s_bdev->bd_inode) >> 9; 357 pr_debug("initial blocksize=%d, #blocks=%d\n", 512, size); 358 359 affs_set_blocksize(sb, PAGE_SIZE); 360 /* Try to find root block. Its location depends on the block size. */ 361 362 i = bdev_logical_block_size(sb->s_bdev); 363 j = PAGE_SIZE; 364 if (blocksize > 0) { 365 i = j = blocksize; 366 size = size / (blocksize / 512); 367 } 368 369 for (blocksize = i; blocksize <= j; blocksize <<= 1, size >>= 1) { 370 sbi->s_root_block = root_block; 371 if (root_block < 0) 372 sbi->s_root_block = (reserved + size - 1) / 2; 373 pr_debug("setting blocksize to %d\n", blocksize); 374 affs_set_blocksize(sb, blocksize); 375 sbi->s_partition_size = size; 376 377 /* The root block location that was calculated above is not 378 * correct if the partition size is an odd number of 512- 379 * byte blocks, which will be rounded down to a number of 380 * 1024-byte blocks, and if there were an even number of 381 * reserved blocks. Ideally, all partition checkers should 382 * report the real number of blocks of the real blocksize, 383 * but since this just cannot be done, we have to try to 384 * find the root block anyways. In the above case, it is one 385 * block behind the calculated one. So we check this one, too. 386 */ 387 for (num_bm = 0; num_bm < 2; num_bm++) { 388 pr_debug("Dev %s, trying root=%u, bs=%d, " 389 "size=%d, reserved=%d\n", 390 sb->s_id, 391 sbi->s_root_block + num_bm, 392 blocksize, size, reserved); 393 root_bh = affs_bread(sb, sbi->s_root_block + num_bm); 394 if (!root_bh) 395 continue; 396 if (!affs_checksum_block(sb, root_bh) && 397 be32_to_cpu(AFFS_ROOT_HEAD(root_bh)->ptype) == T_SHORT && 398 be32_to_cpu(AFFS_ROOT_TAIL(sb, root_bh)->stype) == ST_ROOT) { 399 sbi->s_hashsize = blocksize / 4 - 56; 400 sbi->s_root_block += num_bm; 401 goto got_root; 402 } 403 affs_brelse(root_bh); 404 root_bh = NULL; 405 } 406 } 407 if (!silent) 408 pr_err("No valid root block on device %s\n", sb->s_id); 409 return -EINVAL; 410 411 /* N.B. after this point bh must be released */ 412 got_root: 413 /* Keep super block in cache */ 414 sbi->s_root_bh = root_bh; 415 root_block = sbi->s_root_block; 416 417 /* Find out which kind of FS we have */ 418 boot_bh = sb_bread(sb, 0); 419 if (!boot_bh) { 420 pr_err("Cannot read boot block\n"); 421 return -EINVAL; 422 } 423 memcpy(sig, boot_bh->b_data, 4); 424 brelse(boot_bh); 425 chksum = be32_to_cpu(*(__be32 *)sig); 426 427 /* Dircache filesystems are compatible with non-dircache ones 428 * when reading. As long as they aren't supported, writing is 429 * not recommended. 430 */ 431 if ((chksum == FS_DCFFS || chksum == MUFS_DCFFS || chksum == FS_DCOFS 432 || chksum == MUFS_DCOFS) && !(sb->s_flags & MS_RDONLY)) { 433 pr_notice("Dircache FS - mounting %s read only\n", sb->s_id); 434 sb->s_flags |= MS_RDONLY; 435 } 436 switch (chksum) { 437 case MUFS_FS: 438 case MUFS_INTLFFS: 439 case MUFS_DCFFS: 440 affs_set_opt(sbi->s_flags, SF_MUFS); 441 /* fall thru */ 442 case FS_INTLFFS: 443 case FS_DCFFS: 444 affs_set_opt(sbi->s_flags, SF_INTL); 445 break; 446 case MUFS_FFS: 447 affs_set_opt(sbi->s_flags, SF_MUFS); 448 break; 449 case FS_FFS: 450 break; 451 case MUFS_OFS: 452 affs_set_opt(sbi->s_flags, SF_MUFS); 453 /* fall thru */ 454 case FS_OFS: 455 affs_set_opt(sbi->s_flags, SF_OFS); 456 sb->s_flags |= MS_NOEXEC; 457 break; 458 case MUFS_DCOFS: 459 case MUFS_INTLOFS: 460 affs_set_opt(sbi->s_flags, SF_MUFS); 461 case FS_DCOFS: 462 case FS_INTLOFS: 463 affs_set_opt(sbi->s_flags, SF_INTL); 464 affs_set_opt(sbi->s_flags, SF_OFS); 465 sb->s_flags |= MS_NOEXEC; 466 break; 467 default: 468 pr_err("Unknown filesystem on device %s: %08X\n", 469 sb->s_id, chksum); 470 return -EINVAL; 471 } 472 473 if (affs_test_opt(mount_flags, SF_VERBOSE)) { 474 u8 len = AFFS_ROOT_TAIL(sb, root_bh)->disk_name[0]; 475 pr_notice("Mounting volume \"%.*s\": Type=%.3s\\%c, Blocksize=%d\n", 476 len > 31 ? 31 : len, 477 AFFS_ROOT_TAIL(sb, root_bh)->disk_name + 1, 478 sig, sig[3] + '0', blocksize); 479 } 480 481 sb->s_flags |= MS_NODEV | MS_NOSUID; 482 483 sbi->s_data_blksize = sb->s_blocksize; 484 if (affs_test_opt(sbi->s_flags, SF_OFS)) 485 sbi->s_data_blksize -= 24; 486 487 tmp_flags = sb->s_flags; 488 ret = affs_init_bitmap(sb, &tmp_flags); 489 if (ret) 490 return ret; 491 sb->s_flags = tmp_flags; 492 493 /* set up enough so that it can read an inode */ 494 495 root_inode = affs_iget(sb, root_block); 496 if (IS_ERR(root_inode)) 497 return PTR_ERR(root_inode); 498 499 if (affs_test_opt(AFFS_SB(sb)->s_flags, SF_INTL)) 500 sb->s_d_op = &affs_intl_dentry_operations; 501 else 502 sb->s_d_op = &affs_dentry_operations; 503 504 sb->s_root = d_make_root(root_inode); 505 if (!sb->s_root) { 506 pr_err("AFFS: Get root inode failed\n"); 507 return -ENOMEM; 508 } 509 510 pr_debug("s_flags=%lX\n", sb->s_flags); 511 return 0; 512 } 513 514 static int 515 affs_remount(struct super_block *sb, int *flags, char *data) 516 { 517 struct affs_sb_info *sbi = AFFS_SB(sb); 518 int blocksize; 519 kuid_t uid; 520 kgid_t gid; 521 int mode; 522 int reserved; 523 int root_block; 524 unsigned long mount_flags; 525 int res = 0; 526 char *new_opts; 527 char volume[32]; 528 char *prefix = NULL; 529 530 new_opts = kstrdup(data, GFP_KERNEL); 531 if (!new_opts) 532 return -ENOMEM; 533 534 pr_debug("%s(flags=0x%x,opts=\"%s\")\n", __func__, *flags, data); 535 536 sync_filesystem(sb); 537 *flags |= MS_NODIRATIME; 538 539 memcpy(volume, sbi->s_volume, 32); 540 if (!parse_options(data, &uid, &gid, &mode, &reserved, &root_block, 541 &blocksize, &prefix, volume, 542 &mount_flags)) { 543 kfree(prefix); 544 kfree(new_opts); 545 return -EINVAL; 546 } 547 548 flush_delayed_work(&sbi->sb_work); 549 replace_mount_options(sb, new_opts); 550 551 sbi->s_flags = mount_flags; 552 sbi->s_mode = mode; 553 sbi->s_uid = uid; 554 sbi->s_gid = gid; 555 /* protect against readers */ 556 spin_lock(&sbi->symlink_lock); 557 if (prefix) { 558 kfree(sbi->s_prefix); 559 sbi->s_prefix = prefix; 560 } 561 memcpy(sbi->s_volume, volume, 32); 562 spin_unlock(&sbi->symlink_lock); 563 564 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) 565 return 0; 566 567 if (*flags & MS_RDONLY) 568 affs_free_bitmap(sb); 569 else 570 res = affs_init_bitmap(sb, flags); 571 572 return res; 573 } 574 575 static int 576 affs_statfs(struct dentry *dentry, struct kstatfs *buf) 577 { 578 struct super_block *sb = dentry->d_sb; 579 int free; 580 u64 id = huge_encode_dev(sb->s_bdev->bd_dev); 581 582 pr_debug("%s() partsize=%d, reserved=%d\n", 583 __func__, AFFS_SB(sb)->s_partition_size, 584 AFFS_SB(sb)->s_reserved); 585 586 free = affs_count_free_blocks(sb); 587 buf->f_type = AFFS_SUPER_MAGIC; 588 buf->f_bsize = sb->s_blocksize; 589 buf->f_blocks = AFFS_SB(sb)->s_partition_size - AFFS_SB(sb)->s_reserved; 590 buf->f_bfree = free; 591 buf->f_bavail = free; 592 buf->f_fsid.val[0] = (u32)id; 593 buf->f_fsid.val[1] = (u32)(id >> 32); 594 buf->f_namelen = AFFSNAMEMAX; 595 return 0; 596 } 597 598 static struct dentry *affs_mount(struct file_system_type *fs_type, 599 int flags, const char *dev_name, void *data) 600 { 601 return mount_bdev(fs_type, flags, dev_name, data, affs_fill_super); 602 } 603 604 static void affs_kill_sb(struct super_block *sb) 605 { 606 struct affs_sb_info *sbi = AFFS_SB(sb); 607 kill_block_super(sb); 608 if (sbi) { 609 affs_free_bitmap(sb); 610 affs_brelse(sbi->s_root_bh); 611 kfree(sbi->s_prefix); 612 mutex_destroy(&sbi->s_bmlock); 613 kfree(sbi); 614 } 615 } 616 617 static struct file_system_type affs_fs_type = { 618 .owner = THIS_MODULE, 619 .name = "affs", 620 .mount = affs_mount, 621 .kill_sb = affs_kill_sb, 622 .fs_flags = FS_REQUIRES_DEV, 623 }; 624 MODULE_ALIAS_FS("affs"); 625 626 static int __init init_affs_fs(void) 627 { 628 int err = init_inodecache(); 629 if (err) 630 goto out1; 631 err = register_filesystem(&affs_fs_type); 632 if (err) 633 goto out; 634 return 0; 635 out: 636 destroy_inodecache(); 637 out1: 638 return err; 639 } 640 641 static void __exit exit_affs_fs(void) 642 { 643 unregister_filesystem(&affs_fs_type); 644 destroy_inodecache(); 645 } 646 647 MODULE_DESCRIPTION("Amiga filesystem support for Linux"); 648 MODULE_LICENSE("GPL"); 649 650 module_init(init_affs_fs) 651 module_exit(exit_affs_fs) 652