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/cred.h> 20 #include <linux/slab.h> 21 #include <linux/writeback.h> 22 #include <linux/blkdev.h> 23 #include "affs.h" 24 25 static int affs_statfs(struct dentry *dentry, struct kstatfs *buf); 26 static int affs_remount (struct super_block *sb, int *flags, char *data); 27 28 static void 29 affs_commit_super(struct super_block *sb, int wait) 30 { 31 struct affs_sb_info *sbi = AFFS_SB(sb); 32 struct buffer_head *bh = sbi->s_root_bh; 33 struct affs_root_tail *tail = AFFS_ROOT_TAIL(sb, bh); 34 35 lock_buffer(bh); 36 affs_secs_to_datestamp(ktime_get_real_seconds(), &tail->disk_change); 37 affs_fix_checksum(sb, bh); 38 unlock_buffer(bh); 39 40 mark_buffer_dirty(bh); 41 if (wait) 42 sync_dirty_buffer(bh); 43 } 44 45 static void 46 affs_put_super(struct super_block *sb) 47 { 48 struct affs_sb_info *sbi = AFFS_SB(sb); 49 pr_debug("%s()\n", __func__); 50 51 cancel_delayed_work_sync(&sbi->sb_work); 52 } 53 54 static int 55 affs_sync_fs(struct super_block *sb, int wait) 56 { 57 affs_commit_super(sb, wait); 58 return 0; 59 } 60 61 static void flush_superblock(struct work_struct *work) 62 { 63 struct affs_sb_info *sbi; 64 struct super_block *sb; 65 66 sbi = container_of(work, struct affs_sb_info, sb_work.work); 67 sb = sbi->sb; 68 69 spin_lock(&sbi->work_lock); 70 sbi->work_queued = 0; 71 spin_unlock(&sbi->work_lock); 72 73 affs_commit_super(sb, 1); 74 } 75 76 void affs_mark_sb_dirty(struct super_block *sb) 77 { 78 struct affs_sb_info *sbi = AFFS_SB(sb); 79 unsigned long delay; 80 81 if (sb->s_flags & MS_RDONLY) 82 return; 83 84 spin_lock(&sbi->work_lock); 85 if (!sbi->work_queued) { 86 delay = msecs_to_jiffies(dirty_writeback_interval * 10); 87 queue_delayed_work(system_long_wq, &sbi->sb_work, delay); 88 sbi->work_queued = 1; 89 } 90 spin_unlock(&sbi->work_lock); 91 } 92 93 static struct kmem_cache * affs_inode_cachep; 94 95 static struct inode *affs_alloc_inode(struct super_block *sb) 96 { 97 struct affs_inode_info *i; 98 99 i = kmem_cache_alloc(affs_inode_cachep, GFP_KERNEL); 100 if (!i) 101 return NULL; 102 103 i->vfs_inode.i_version = 1; 104 i->i_lc = NULL; 105 i->i_ext_bh = NULL; 106 i->i_pa_cnt = 0; 107 108 return &i->vfs_inode; 109 } 110 111 static void affs_i_callback(struct rcu_head *head) 112 { 113 struct inode *inode = container_of(head, struct inode, i_rcu); 114 kmem_cache_free(affs_inode_cachep, AFFS_I(inode)); 115 } 116 117 static void affs_destroy_inode(struct inode *inode) 118 { 119 call_rcu(&inode->i_rcu, affs_i_callback); 120 } 121 122 static void init_once(void *foo) 123 { 124 struct affs_inode_info *ei = (struct affs_inode_info *) foo; 125 126 sema_init(&ei->i_link_lock, 1); 127 sema_init(&ei->i_ext_lock, 1); 128 inode_init_once(&ei->vfs_inode); 129 } 130 131 static int __init init_inodecache(void) 132 { 133 affs_inode_cachep = kmem_cache_create("affs_inode_cache", 134 sizeof(struct affs_inode_info), 135 0, (SLAB_RECLAIM_ACCOUNT| 136 SLAB_MEM_SPREAD|SLAB_ACCOUNT), 137 init_once); 138 if (affs_inode_cachep == NULL) 139 return -ENOMEM; 140 return 0; 141 } 142 143 static void destroy_inodecache(void) 144 { 145 /* 146 * Make sure all delayed rcu free inodes are flushed before we 147 * destroy cache. 148 */ 149 rcu_barrier(); 150 kmem_cache_destroy(affs_inode_cachep); 151 } 152 153 static const struct super_operations affs_sops = { 154 .alloc_inode = affs_alloc_inode, 155 .destroy_inode = affs_destroy_inode, 156 .write_inode = affs_write_inode, 157 .evict_inode = affs_evict_inode, 158 .put_super = affs_put_super, 159 .sync_fs = affs_sync_fs, 160 .statfs = affs_statfs, 161 .remount_fs = affs_remount, 162 .show_options = generic_show_options, 163 }; 164 165 enum { 166 Opt_bs, Opt_mode, Opt_mufs, Opt_notruncate, Opt_prefix, Opt_protect, 167 Opt_reserved, Opt_root, Opt_setgid, Opt_setuid, 168 Opt_verbose, Opt_volume, Opt_ignore, Opt_err, 169 }; 170 171 static const match_table_t tokens = { 172 {Opt_bs, "bs=%u"}, 173 {Opt_mode, "mode=%o"}, 174 {Opt_mufs, "mufs"}, 175 {Opt_notruncate, "nofilenametruncate"}, 176 {Opt_prefix, "prefix=%s"}, 177 {Opt_protect, "protect"}, 178 {Opt_reserved, "reserved=%u"}, 179 {Opt_root, "root=%u"}, 180 {Opt_setgid, "setgid=%u"}, 181 {Opt_setuid, "setuid=%u"}, 182 {Opt_verbose, "verbose"}, 183 {Opt_volume, "volume=%s"}, 184 {Opt_ignore, "grpquota"}, 185 {Opt_ignore, "noquota"}, 186 {Opt_ignore, "quota"}, 187 {Opt_ignore, "usrquota"}, 188 {Opt_err, NULL}, 189 }; 190 191 static int 192 parse_options(char *options, kuid_t *uid, kgid_t *gid, int *mode, int *reserved, s32 *root, 193 int *blocksize, char **prefix, char *volume, unsigned long *mount_opts) 194 { 195 char *p; 196 substring_t args[MAX_OPT_ARGS]; 197 198 /* Fill in defaults */ 199 200 *uid = current_uid(); 201 *gid = current_gid(); 202 *reserved = 2; 203 *root = -1; 204 *blocksize = -1; 205 volume[0] = ':'; 206 volume[1] = 0; 207 *mount_opts = 0; 208 if (!options) 209 return 1; 210 211 while ((p = strsep(&options, ",")) != NULL) { 212 int token, n, option; 213 if (!*p) 214 continue; 215 216 token = match_token(p, tokens, args); 217 switch (token) { 218 case Opt_bs: 219 if (match_int(&args[0], &n)) 220 return 0; 221 if (n != 512 && n != 1024 && n != 2048 222 && n != 4096) { 223 pr_warn("Invalid blocksize (512, 1024, 2048, 4096 allowed)\n"); 224 return 0; 225 } 226 *blocksize = n; 227 break; 228 case Opt_mode: 229 if (match_octal(&args[0], &option)) 230 return 0; 231 *mode = option & 0777; 232 affs_set_opt(*mount_opts, SF_SETMODE); 233 break; 234 case Opt_mufs: 235 affs_set_opt(*mount_opts, SF_MUFS); 236 break; 237 case Opt_notruncate: 238 affs_set_opt(*mount_opts, SF_NO_TRUNCATE); 239 break; 240 case Opt_prefix: 241 *prefix = match_strdup(&args[0]); 242 if (!*prefix) 243 return 0; 244 affs_set_opt(*mount_opts, SF_PREFIX); 245 break; 246 case Opt_protect: 247 affs_set_opt(*mount_opts, SF_IMMUTABLE); 248 break; 249 case Opt_reserved: 250 if (match_int(&args[0], reserved)) 251 return 0; 252 break; 253 case Opt_root: 254 if (match_int(&args[0], root)) 255 return 0; 256 break; 257 case Opt_setgid: 258 if (match_int(&args[0], &option)) 259 return 0; 260 *gid = make_kgid(current_user_ns(), option); 261 if (!gid_valid(*gid)) 262 return 0; 263 affs_set_opt(*mount_opts, SF_SETGID); 264 break; 265 case Opt_setuid: 266 if (match_int(&args[0], &option)) 267 return 0; 268 *uid = make_kuid(current_user_ns(), option); 269 if (!uid_valid(*uid)) 270 return 0; 271 affs_set_opt(*mount_opts, SF_SETUID); 272 break; 273 case Opt_verbose: 274 affs_set_opt(*mount_opts, SF_VERBOSE); 275 break; 276 case Opt_volume: { 277 char *vol = match_strdup(&args[0]); 278 if (!vol) 279 return 0; 280 strlcpy(volume, vol, 32); 281 kfree(vol); 282 break; 283 } 284 case Opt_ignore: 285 /* Silently ignore the quota options */ 286 break; 287 default: 288 pr_warn("Unrecognized mount option \"%s\" or missing value\n", 289 p); 290 return 0; 291 } 292 } 293 return 1; 294 } 295 296 /* This function definitely needs to be split up. Some fine day I'll 297 * hopefully have the guts to do so. Until then: sorry for the mess. 298 */ 299 300 static int affs_fill_super(struct super_block *sb, void *data, int silent) 301 { 302 struct affs_sb_info *sbi; 303 struct buffer_head *root_bh = NULL; 304 struct buffer_head *boot_bh; 305 struct inode *root_inode = NULL; 306 s32 root_block; 307 int size, blocksize; 308 u32 chksum; 309 int num_bm; 310 int i, j; 311 kuid_t uid; 312 kgid_t gid; 313 int reserved; 314 unsigned long mount_flags; 315 int tmp_flags; /* fix remount prototype... */ 316 u8 sig[4]; 317 int ret; 318 319 save_mount_options(sb, data); 320 321 pr_debug("read_super(%s)\n", data ? (const char *)data : "no options"); 322 323 sb->s_magic = AFFS_SUPER_MAGIC; 324 sb->s_op = &affs_sops; 325 sb->s_flags |= MS_NODIRATIME; 326 327 sbi = kzalloc(sizeof(struct affs_sb_info), GFP_KERNEL); 328 if (!sbi) 329 return -ENOMEM; 330 331 sb->s_fs_info = sbi; 332 sbi->sb = sb; 333 mutex_init(&sbi->s_bmlock); 334 spin_lock_init(&sbi->symlink_lock); 335 spin_lock_init(&sbi->work_lock); 336 INIT_DELAYED_WORK(&sbi->sb_work, flush_superblock); 337 338 if (!parse_options(data,&uid,&gid,&i,&reserved,&root_block, 339 &blocksize,&sbi->s_prefix, 340 sbi->s_volume, &mount_flags)) { 341 pr_err("Error parsing options\n"); 342 return -EINVAL; 343 } 344 /* N.B. after this point s_prefix must be released */ 345 346 sbi->s_flags = mount_flags; 347 sbi->s_mode = i; 348 sbi->s_uid = uid; 349 sbi->s_gid = gid; 350 sbi->s_reserved= reserved; 351 352 /* Get the size of the device in 512-byte blocks. 353 * If we later see that the partition uses bigger 354 * blocks, we will have to change it. 355 */ 356 357 size = i_size_read(sb->s_bdev->bd_inode) >> 9; 358 pr_debug("initial blocksize=%d, #blocks=%d\n", 512, size); 359 360 affs_set_blocksize(sb, PAGE_SIZE); 361 /* Try to find root block. Its location depends on the block size. */ 362 363 i = bdev_logical_block_size(sb->s_bdev); 364 j = PAGE_SIZE; 365 if (blocksize > 0) { 366 i = j = blocksize; 367 size = size / (blocksize / 512); 368 } 369 370 for (blocksize = i; blocksize <= j; blocksize <<= 1, size >>= 1) { 371 sbi->s_root_block = root_block; 372 if (root_block < 0) 373 sbi->s_root_block = (reserved + size - 1) / 2; 374 pr_debug("setting blocksize to %d\n", blocksize); 375 affs_set_blocksize(sb, blocksize); 376 sbi->s_partition_size = size; 377 378 /* The root block location that was calculated above is not 379 * correct if the partition size is an odd number of 512- 380 * byte blocks, which will be rounded down to a number of 381 * 1024-byte blocks, and if there were an even number of 382 * reserved blocks. Ideally, all partition checkers should 383 * report the real number of blocks of the real blocksize, 384 * but since this just cannot be done, we have to try to 385 * find the root block anyways. In the above case, it is one 386 * block behind the calculated one. So we check this one, too. 387 */ 388 for (num_bm = 0; num_bm < 2; num_bm++) { 389 pr_debug("Dev %s, trying root=%u, bs=%d, " 390 "size=%d, reserved=%d\n", 391 sb->s_id, 392 sbi->s_root_block + num_bm, 393 blocksize, size, reserved); 394 root_bh = affs_bread(sb, sbi->s_root_block + num_bm); 395 if (!root_bh) 396 continue; 397 if (!affs_checksum_block(sb, root_bh) && 398 be32_to_cpu(AFFS_ROOT_HEAD(root_bh)->ptype) == T_SHORT && 399 be32_to_cpu(AFFS_ROOT_TAIL(sb, root_bh)->stype) == ST_ROOT) { 400 sbi->s_hashsize = blocksize / 4 - 56; 401 sbi->s_root_block += num_bm; 402 goto got_root; 403 } 404 affs_brelse(root_bh); 405 root_bh = NULL; 406 } 407 } 408 if (!silent) 409 pr_err("No valid root block on device %s\n", sb->s_id); 410 return -EINVAL; 411 412 /* N.B. after this point bh must be released */ 413 got_root: 414 /* Keep super block in cache */ 415 sbi->s_root_bh = root_bh; 416 root_block = sbi->s_root_block; 417 418 /* Find out which kind of FS we have */ 419 boot_bh = sb_bread(sb, 0); 420 if (!boot_bh) { 421 pr_err("Cannot read boot block\n"); 422 return -EINVAL; 423 } 424 memcpy(sig, boot_bh->b_data, 4); 425 brelse(boot_bh); 426 chksum = be32_to_cpu(*(__be32 *)sig); 427 428 /* Dircache filesystems are compatible with non-dircache ones 429 * when reading. As long as they aren't supported, writing is 430 * not recommended. 431 */ 432 if ((chksum == FS_DCFFS || chksum == MUFS_DCFFS || chksum == FS_DCOFS 433 || chksum == MUFS_DCOFS) && !(sb->s_flags & MS_RDONLY)) { 434 pr_notice("Dircache FS - mounting %s read only\n", sb->s_id); 435 sb->s_flags |= MS_RDONLY; 436 } 437 switch (chksum) { 438 case MUFS_FS: 439 case MUFS_INTLFFS: 440 case MUFS_DCFFS: 441 affs_set_opt(sbi->s_flags, SF_MUFS); 442 /* fall thru */ 443 case FS_INTLFFS: 444 case FS_DCFFS: 445 affs_set_opt(sbi->s_flags, SF_INTL); 446 break; 447 case MUFS_FFS: 448 affs_set_opt(sbi->s_flags, SF_MUFS); 449 break; 450 case FS_FFS: 451 break; 452 case MUFS_OFS: 453 affs_set_opt(sbi->s_flags, SF_MUFS); 454 /* fall thru */ 455 case FS_OFS: 456 affs_set_opt(sbi->s_flags, SF_OFS); 457 sb->s_flags |= MS_NOEXEC; 458 break; 459 case MUFS_DCOFS: 460 case MUFS_INTLOFS: 461 affs_set_opt(sbi->s_flags, SF_MUFS); 462 case FS_DCOFS: 463 case FS_INTLOFS: 464 affs_set_opt(sbi->s_flags, SF_INTL); 465 affs_set_opt(sbi->s_flags, SF_OFS); 466 sb->s_flags |= MS_NOEXEC; 467 break; 468 default: 469 pr_err("Unknown filesystem on device %s: %08X\n", 470 sb->s_id, chksum); 471 return -EINVAL; 472 } 473 474 if (affs_test_opt(mount_flags, SF_VERBOSE)) { 475 u8 len = AFFS_ROOT_TAIL(sb, root_bh)->disk_name[0]; 476 pr_notice("Mounting volume \"%.*s\": Type=%.3s\\%c, Blocksize=%d\n", 477 len > 31 ? 31 : len, 478 AFFS_ROOT_TAIL(sb, root_bh)->disk_name + 1, 479 sig, sig[3] + '0', blocksize); 480 } 481 482 sb->s_flags |= MS_NODEV | MS_NOSUID; 483 484 sbi->s_data_blksize = sb->s_blocksize; 485 if (affs_test_opt(sbi->s_flags, SF_OFS)) 486 sbi->s_data_blksize -= 24; 487 488 tmp_flags = sb->s_flags; 489 ret = affs_init_bitmap(sb, &tmp_flags); 490 if (ret) 491 return ret; 492 sb->s_flags = tmp_flags; 493 494 /* set up enough so that it can read an inode */ 495 496 root_inode = affs_iget(sb, root_block); 497 if (IS_ERR(root_inode)) 498 return PTR_ERR(root_inode); 499 500 if (affs_test_opt(AFFS_SB(sb)->s_flags, SF_INTL)) 501 sb->s_d_op = &affs_intl_dentry_operations; 502 else 503 sb->s_d_op = &affs_dentry_operations; 504 505 sb->s_root = d_make_root(root_inode); 506 if (!sb->s_root) { 507 pr_err("AFFS: Get root inode failed\n"); 508 return -ENOMEM; 509 } 510 511 sb->s_export_op = &affs_export_ops; 512 pr_debug("s_flags=%lX\n", sb->s_flags); 513 return 0; 514 } 515 516 static int 517 affs_remount(struct super_block *sb, int *flags, char *data) 518 { 519 struct affs_sb_info *sbi = AFFS_SB(sb); 520 int blocksize; 521 kuid_t uid; 522 kgid_t gid; 523 int mode; 524 int reserved; 525 int root_block; 526 unsigned long mount_flags; 527 int res = 0; 528 char *new_opts; 529 char volume[32]; 530 char *prefix = NULL; 531 532 new_opts = kstrdup(data, GFP_KERNEL); 533 if (data && !new_opts) 534 return -ENOMEM; 535 536 pr_debug("%s(flags=0x%x,opts=\"%s\")\n", __func__, *flags, data); 537 538 sync_filesystem(sb); 539 *flags |= MS_NODIRATIME; 540 541 memcpy(volume, sbi->s_volume, 32); 542 if (!parse_options(data, &uid, &gid, &mode, &reserved, &root_block, 543 &blocksize, &prefix, volume, 544 &mount_flags)) { 545 kfree(prefix); 546 kfree(new_opts); 547 return -EINVAL; 548 } 549 550 flush_delayed_work(&sbi->sb_work); 551 if (new_opts) 552 replace_mount_options(sb, new_opts); 553 554 sbi->s_flags = mount_flags; 555 sbi->s_mode = mode; 556 sbi->s_uid = uid; 557 sbi->s_gid = gid; 558 /* protect against readers */ 559 spin_lock(&sbi->symlink_lock); 560 if (prefix) { 561 kfree(sbi->s_prefix); 562 sbi->s_prefix = prefix; 563 } 564 memcpy(sbi->s_volume, volume, 32); 565 spin_unlock(&sbi->symlink_lock); 566 567 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) 568 return 0; 569 570 if (*flags & MS_RDONLY) 571 affs_free_bitmap(sb); 572 else 573 res = affs_init_bitmap(sb, flags); 574 575 return res; 576 } 577 578 static int 579 affs_statfs(struct dentry *dentry, struct kstatfs *buf) 580 { 581 struct super_block *sb = dentry->d_sb; 582 int free; 583 u64 id = huge_encode_dev(sb->s_bdev->bd_dev); 584 585 pr_debug("%s() partsize=%d, reserved=%d\n", 586 __func__, AFFS_SB(sb)->s_partition_size, 587 AFFS_SB(sb)->s_reserved); 588 589 free = affs_count_free_blocks(sb); 590 buf->f_type = AFFS_SUPER_MAGIC; 591 buf->f_bsize = sb->s_blocksize; 592 buf->f_blocks = AFFS_SB(sb)->s_partition_size - AFFS_SB(sb)->s_reserved; 593 buf->f_bfree = free; 594 buf->f_bavail = free; 595 buf->f_fsid.val[0] = (u32)id; 596 buf->f_fsid.val[1] = (u32)(id >> 32); 597 buf->f_namelen = AFFSNAMEMAX; 598 return 0; 599 } 600 601 static struct dentry *affs_mount(struct file_system_type *fs_type, 602 int flags, const char *dev_name, void *data) 603 { 604 return mount_bdev(fs_type, flags, dev_name, data, affs_fill_super); 605 } 606 607 static void affs_kill_sb(struct super_block *sb) 608 { 609 struct affs_sb_info *sbi = AFFS_SB(sb); 610 kill_block_super(sb); 611 if (sbi) { 612 affs_free_bitmap(sb); 613 affs_brelse(sbi->s_root_bh); 614 kfree(sbi->s_prefix); 615 mutex_destroy(&sbi->s_bmlock); 616 kfree(sbi); 617 } 618 } 619 620 static struct file_system_type affs_fs_type = { 621 .owner = THIS_MODULE, 622 .name = "affs", 623 .mount = affs_mount, 624 .kill_sb = affs_kill_sb, 625 .fs_flags = FS_REQUIRES_DEV, 626 }; 627 MODULE_ALIAS_FS("affs"); 628 629 static int __init init_affs_fs(void) 630 { 631 int err = init_inodecache(); 632 if (err) 633 goto out1; 634 err = register_filesystem(&affs_fs_type); 635 if (err) 636 goto out; 637 return 0; 638 out: 639 destroy_inodecache(); 640 out1: 641 return err; 642 } 643 644 static void __exit exit_affs_fs(void) 645 { 646 unregister_filesystem(&affs_fs_type); 647 destroy_inodecache(); 648 } 649 650 MODULE_DESCRIPTION("Amiga filesystem support for Linux"); 651 MODULE_LICENSE("GPL"); 652 653 module_init(init_affs_fs) 654 module_exit(exit_affs_fs) 655