1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * linux/fs/affs/inode.c 4 * 5 * (c) 1996 Hans-Joachim Widmaier - Rewritten 6 * 7 * (C) 1993 Ray Burr - Modified for Amiga FFS filesystem. 8 * 9 * (C) 1992 Eric Youngdale Modified for ISO 9660 filesystem. 10 * 11 * (C) 1991 Linus Torvalds - minix filesystem 12 */ 13 14 #include <linux/module.h> 15 #include <linux/init.h> 16 #include <linux/statfs.h> 17 #include <linux/parser.h> 18 #include <linux/magic.h> 19 #include <linux/sched.h> 20 #include <linux/cred.h> 21 #include <linux/slab.h> 22 #include <linux/writeback.h> 23 #include <linux/blkdev.h> 24 #include <linux/seq_file.h> 25 #include <linux/iversion.h> 26 #include "affs.h" 27 28 static int affs_statfs(struct dentry *dentry, struct kstatfs *buf); 29 static int affs_show_options(struct seq_file *m, struct dentry *root); 30 static int affs_remount (struct super_block *sb, int *flags, char *data); 31 32 static void 33 affs_commit_super(struct super_block *sb, int wait) 34 { 35 struct affs_sb_info *sbi = AFFS_SB(sb); 36 struct buffer_head *bh = sbi->s_root_bh; 37 struct affs_root_tail *tail = AFFS_ROOT_TAIL(sb, bh); 38 39 lock_buffer(bh); 40 affs_secs_to_datestamp(ktime_get_real_seconds(), &tail->disk_change); 41 affs_fix_checksum(sb, bh); 42 unlock_buffer(bh); 43 44 mark_buffer_dirty(bh); 45 if (wait) 46 sync_dirty_buffer(bh); 47 } 48 49 static void 50 affs_put_super(struct super_block *sb) 51 { 52 struct affs_sb_info *sbi = AFFS_SB(sb); 53 pr_debug("%s()\n", __func__); 54 55 cancel_delayed_work_sync(&sbi->sb_work); 56 } 57 58 static int 59 affs_sync_fs(struct super_block *sb, int wait) 60 { 61 affs_commit_super(sb, wait); 62 return 0; 63 } 64 65 static void flush_superblock(struct work_struct *work) 66 { 67 struct affs_sb_info *sbi; 68 struct super_block *sb; 69 70 sbi = container_of(work, struct affs_sb_info, sb_work.work); 71 sb = sbi->sb; 72 73 spin_lock(&sbi->work_lock); 74 sbi->work_queued = 0; 75 spin_unlock(&sbi->work_lock); 76 77 affs_commit_super(sb, 1); 78 } 79 80 void affs_mark_sb_dirty(struct super_block *sb) 81 { 82 struct affs_sb_info *sbi = AFFS_SB(sb); 83 unsigned long delay; 84 85 if (sb_rdonly(sb)) 86 return; 87 88 spin_lock(&sbi->work_lock); 89 if (!sbi->work_queued) { 90 delay = msecs_to_jiffies(dirty_writeback_interval * 10); 91 queue_delayed_work(system_long_wq, &sbi->sb_work, delay); 92 sbi->work_queued = 1; 93 } 94 spin_unlock(&sbi->work_lock); 95 } 96 97 static struct kmem_cache * affs_inode_cachep; 98 99 static struct inode *affs_alloc_inode(struct super_block *sb) 100 { 101 struct affs_inode_info *i; 102 103 i = kmem_cache_alloc(affs_inode_cachep, GFP_KERNEL); 104 if (!i) 105 return NULL; 106 107 inode_set_iversion(&i->vfs_inode, 1); 108 i->i_lc = NULL; 109 i->i_ext_bh = NULL; 110 i->i_pa_cnt = 0; 111 112 return &i->vfs_inode; 113 } 114 115 static void affs_free_inode(struct inode *inode) 116 { 117 kmem_cache_free(affs_inode_cachep, AFFS_I(inode)); 118 } 119 120 static void init_once(void *foo) 121 { 122 struct affs_inode_info *ei = (struct affs_inode_info *) foo; 123 124 mutex_init(&ei->i_link_lock); 125 mutex_init(&ei->i_ext_lock); 126 inode_init_once(&ei->vfs_inode); 127 } 128 129 static int __init init_inodecache(void) 130 { 131 affs_inode_cachep = kmem_cache_create("affs_inode_cache", 132 sizeof(struct affs_inode_info), 133 0, (SLAB_RECLAIM_ACCOUNT| 134 SLAB_MEM_SPREAD|SLAB_ACCOUNT), 135 init_once); 136 if (affs_inode_cachep == NULL) 137 return -ENOMEM; 138 return 0; 139 } 140 141 static void destroy_inodecache(void) 142 { 143 /* 144 * Make sure all delayed rcu free inodes are flushed before we 145 * destroy cache. 146 */ 147 rcu_barrier(); 148 kmem_cache_destroy(affs_inode_cachep); 149 } 150 151 static const struct super_operations affs_sops = { 152 .alloc_inode = affs_alloc_inode, 153 .free_inode = affs_free_inode, 154 .write_inode = affs_write_inode, 155 .evict_inode = affs_evict_inode, 156 .put_super = affs_put_super, 157 .sync_fs = affs_sync_fs, 158 .statfs = affs_statfs, 159 .remount_fs = affs_remount, 160 .show_options = affs_show_options, 161 }; 162 163 enum { 164 Opt_bs, Opt_mode, Opt_mufs, Opt_notruncate, Opt_prefix, Opt_protect, 165 Opt_reserved, Opt_root, Opt_setgid, Opt_setuid, 166 Opt_verbose, Opt_volume, Opt_ignore, Opt_err, 167 }; 168 169 static const match_table_t tokens = { 170 {Opt_bs, "bs=%u"}, 171 {Opt_mode, "mode=%o"}, 172 {Opt_mufs, "mufs"}, 173 {Opt_notruncate, "nofilenametruncate"}, 174 {Opt_prefix, "prefix=%s"}, 175 {Opt_protect, "protect"}, 176 {Opt_reserved, "reserved=%u"}, 177 {Opt_root, "root=%u"}, 178 {Opt_setgid, "setgid=%u"}, 179 {Opt_setuid, "setuid=%u"}, 180 {Opt_verbose, "verbose"}, 181 {Opt_volume, "volume=%s"}, 182 {Opt_ignore, "grpquota"}, 183 {Opt_ignore, "noquota"}, 184 {Opt_ignore, "quota"}, 185 {Opt_ignore, "usrquota"}, 186 {Opt_err, NULL}, 187 }; 188 189 static int 190 parse_options(char *options, kuid_t *uid, kgid_t *gid, int *mode, int *reserved, s32 *root, 191 int *blocksize, char **prefix, char *volume, unsigned long *mount_opts) 192 { 193 char *p; 194 substring_t args[MAX_OPT_ARGS]; 195 196 /* Fill in defaults */ 197 198 *uid = current_uid(); 199 *gid = current_gid(); 200 *reserved = 2; 201 *root = -1; 202 *blocksize = -1; 203 volume[0] = ':'; 204 volume[1] = 0; 205 *mount_opts = 0; 206 if (!options) 207 return 1; 208 209 while ((p = strsep(&options, ",")) != NULL) { 210 int token, n, option; 211 if (!*p) 212 continue; 213 214 token = match_token(p, tokens, args); 215 switch (token) { 216 case Opt_bs: 217 if (match_int(&args[0], &n)) 218 return 0; 219 if (n != 512 && n != 1024 && n != 2048 220 && n != 4096) { 221 pr_warn("Invalid blocksize (512, 1024, 2048, 4096 allowed)\n"); 222 return 0; 223 } 224 *blocksize = n; 225 break; 226 case Opt_mode: 227 if (match_octal(&args[0], &option)) 228 return 0; 229 *mode = option & 0777; 230 affs_set_opt(*mount_opts, SF_SETMODE); 231 break; 232 case Opt_mufs: 233 affs_set_opt(*mount_opts, SF_MUFS); 234 break; 235 case Opt_notruncate: 236 affs_set_opt(*mount_opts, SF_NO_TRUNCATE); 237 break; 238 case Opt_prefix: 239 kfree(*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 static int affs_show_options(struct seq_file *m, struct dentry *root) 296 { 297 struct super_block *sb = root->d_sb; 298 struct affs_sb_info *sbi = AFFS_SB(sb); 299 300 if (sb->s_blocksize) 301 seq_printf(m, ",bs=%lu", sb->s_blocksize); 302 if (affs_test_opt(sbi->s_flags, SF_SETMODE)) 303 seq_printf(m, ",mode=%o", sbi->s_mode); 304 if (affs_test_opt(sbi->s_flags, SF_MUFS)) 305 seq_puts(m, ",mufs"); 306 if (affs_test_opt(sbi->s_flags, SF_NO_TRUNCATE)) 307 seq_puts(m, ",nofilenametruncate"); 308 if (affs_test_opt(sbi->s_flags, SF_PREFIX)) 309 seq_printf(m, ",prefix=%s", sbi->s_prefix); 310 if (affs_test_opt(sbi->s_flags, SF_IMMUTABLE)) 311 seq_puts(m, ",protect"); 312 if (sbi->s_reserved != 2) 313 seq_printf(m, ",reserved=%u", sbi->s_reserved); 314 if (sbi->s_root_block != (sbi->s_reserved + sbi->s_partition_size - 1) / 2) 315 seq_printf(m, ",root=%u", sbi->s_root_block); 316 if (affs_test_opt(sbi->s_flags, SF_SETGID)) 317 seq_printf(m, ",setgid=%u", 318 from_kgid_munged(&init_user_ns, sbi->s_gid)); 319 if (affs_test_opt(sbi->s_flags, SF_SETUID)) 320 seq_printf(m, ",setuid=%u", 321 from_kuid_munged(&init_user_ns, sbi->s_uid)); 322 if (affs_test_opt(sbi->s_flags, SF_VERBOSE)) 323 seq_puts(m, ",verbose"); 324 if (sbi->s_volume[0]) 325 seq_printf(m, ",volume=%s", sbi->s_volume); 326 return 0; 327 } 328 329 /* This function definitely needs to be split up. Some fine day I'll 330 * hopefully have the guts to do so. Until then: sorry for the mess. 331 */ 332 333 static int affs_fill_super(struct super_block *sb, void *data, int silent) 334 { 335 struct affs_sb_info *sbi; 336 struct buffer_head *root_bh = NULL; 337 struct buffer_head *boot_bh; 338 struct inode *root_inode = NULL; 339 s32 root_block; 340 int size, blocksize; 341 u32 chksum; 342 int num_bm; 343 int i, j; 344 kuid_t uid; 345 kgid_t gid; 346 int reserved; 347 unsigned long mount_flags; 348 int tmp_flags; /* fix remount prototype... */ 349 u8 sig[4]; 350 int ret; 351 352 pr_debug("read_super(%s)\n", data ? (const char *)data : "no options"); 353 354 sb->s_magic = AFFS_SUPER_MAGIC; 355 sb->s_op = &affs_sops; 356 sb->s_flags |= SB_NODIRATIME; 357 358 sb->s_time_gran = NSEC_PER_SEC; 359 sb->s_time_min = sys_tz.tz_minuteswest * 60 + AFFS_EPOCH_DELTA; 360 sb->s_time_max = 86400LL * U32_MAX + 86400 + sb->s_time_min; 361 362 sbi = kzalloc(sizeof(struct affs_sb_info), GFP_KERNEL); 363 if (!sbi) 364 return -ENOMEM; 365 366 sb->s_fs_info = sbi; 367 sbi->sb = sb; 368 mutex_init(&sbi->s_bmlock); 369 spin_lock_init(&sbi->symlink_lock); 370 spin_lock_init(&sbi->work_lock); 371 INIT_DELAYED_WORK(&sbi->sb_work, flush_superblock); 372 373 if (!parse_options(data,&uid,&gid,&i,&reserved,&root_block, 374 &blocksize,&sbi->s_prefix, 375 sbi->s_volume, &mount_flags)) { 376 pr_err("Error parsing options\n"); 377 return -EINVAL; 378 } 379 /* N.B. after this point s_prefix must be released */ 380 381 sbi->s_flags = mount_flags; 382 sbi->s_mode = i; 383 sbi->s_uid = uid; 384 sbi->s_gid = gid; 385 sbi->s_reserved= reserved; 386 387 /* Get the size of the device in 512-byte blocks. 388 * If we later see that the partition uses bigger 389 * blocks, we will have to change it. 390 */ 391 392 size = i_size_read(sb->s_bdev->bd_inode) >> 9; 393 pr_debug("initial blocksize=%d, #blocks=%d\n", 512, size); 394 395 affs_set_blocksize(sb, PAGE_SIZE); 396 /* Try to find root block. Its location depends on the block size. */ 397 398 i = bdev_logical_block_size(sb->s_bdev); 399 j = PAGE_SIZE; 400 if (blocksize > 0) { 401 i = j = blocksize; 402 size = size / (blocksize / 512); 403 } 404 405 for (blocksize = i; blocksize <= j; blocksize <<= 1, size >>= 1) { 406 sbi->s_root_block = root_block; 407 if (root_block < 0) 408 sbi->s_root_block = (reserved + size - 1) / 2; 409 pr_debug("setting blocksize to %d\n", blocksize); 410 affs_set_blocksize(sb, blocksize); 411 sbi->s_partition_size = size; 412 413 /* The root block location that was calculated above is not 414 * correct if the partition size is an odd number of 512- 415 * byte blocks, which will be rounded down to a number of 416 * 1024-byte blocks, and if there were an even number of 417 * reserved blocks. Ideally, all partition checkers should 418 * report the real number of blocks of the real blocksize, 419 * but since this just cannot be done, we have to try to 420 * find the root block anyways. In the above case, it is one 421 * block behind the calculated one. So we check this one, too. 422 */ 423 for (num_bm = 0; num_bm < 2; num_bm++) { 424 pr_debug("Dev %s, trying root=%u, bs=%d, " 425 "size=%d, reserved=%d\n", 426 sb->s_id, 427 sbi->s_root_block + num_bm, 428 blocksize, size, reserved); 429 root_bh = affs_bread(sb, sbi->s_root_block + num_bm); 430 if (!root_bh) 431 continue; 432 if (!affs_checksum_block(sb, root_bh) && 433 be32_to_cpu(AFFS_ROOT_HEAD(root_bh)->ptype) == T_SHORT && 434 be32_to_cpu(AFFS_ROOT_TAIL(sb, root_bh)->stype) == ST_ROOT) { 435 sbi->s_hashsize = blocksize / 4 - 56; 436 sbi->s_root_block += num_bm; 437 goto got_root; 438 } 439 affs_brelse(root_bh); 440 root_bh = NULL; 441 } 442 } 443 if (!silent) 444 pr_err("No valid root block on device %s\n", sb->s_id); 445 return -EINVAL; 446 447 /* N.B. after this point bh must be released */ 448 got_root: 449 /* Keep super block in cache */ 450 sbi->s_root_bh = root_bh; 451 root_block = sbi->s_root_block; 452 453 /* Find out which kind of FS we have */ 454 boot_bh = sb_bread(sb, 0); 455 if (!boot_bh) { 456 pr_err("Cannot read boot block\n"); 457 return -EINVAL; 458 } 459 memcpy(sig, boot_bh->b_data, 4); 460 brelse(boot_bh); 461 chksum = be32_to_cpu(*(__be32 *)sig); 462 463 /* Dircache filesystems are compatible with non-dircache ones 464 * when reading. As long as they aren't supported, writing is 465 * not recommended. 466 */ 467 if ((chksum == FS_DCFFS || chksum == MUFS_DCFFS || chksum == FS_DCOFS 468 || chksum == MUFS_DCOFS) && !sb_rdonly(sb)) { 469 pr_notice("Dircache FS - mounting %s read only\n", sb->s_id); 470 sb->s_flags |= SB_RDONLY; 471 } 472 switch (chksum) { 473 case MUFS_FS: 474 case MUFS_INTLFFS: 475 case MUFS_DCFFS: 476 affs_set_opt(sbi->s_flags, SF_MUFS); 477 /* fall thru */ 478 case FS_INTLFFS: 479 case FS_DCFFS: 480 affs_set_opt(sbi->s_flags, SF_INTL); 481 break; 482 case MUFS_FFS: 483 affs_set_opt(sbi->s_flags, SF_MUFS); 484 break; 485 case FS_FFS: 486 break; 487 case MUFS_OFS: 488 affs_set_opt(sbi->s_flags, SF_MUFS); 489 /* fall through */ 490 case FS_OFS: 491 affs_set_opt(sbi->s_flags, SF_OFS); 492 sb->s_flags |= SB_NOEXEC; 493 break; 494 case MUFS_DCOFS: 495 case MUFS_INTLOFS: 496 affs_set_opt(sbi->s_flags, SF_MUFS); 497 /* fall through */ 498 case FS_DCOFS: 499 case FS_INTLOFS: 500 affs_set_opt(sbi->s_flags, SF_INTL); 501 affs_set_opt(sbi->s_flags, SF_OFS); 502 sb->s_flags |= SB_NOEXEC; 503 break; 504 default: 505 pr_err("Unknown filesystem on device %s: %08X\n", 506 sb->s_id, chksum); 507 return -EINVAL; 508 } 509 510 if (affs_test_opt(mount_flags, SF_VERBOSE)) { 511 u8 len = AFFS_ROOT_TAIL(sb, root_bh)->disk_name[0]; 512 pr_notice("Mounting volume \"%.*s\": Type=%.3s\\%c, Blocksize=%d\n", 513 len > 31 ? 31 : len, 514 AFFS_ROOT_TAIL(sb, root_bh)->disk_name + 1, 515 sig, sig[3] + '0', blocksize); 516 } 517 518 sb->s_flags |= SB_NODEV | SB_NOSUID; 519 520 sbi->s_data_blksize = sb->s_blocksize; 521 if (affs_test_opt(sbi->s_flags, SF_OFS)) 522 sbi->s_data_blksize -= 24; 523 524 tmp_flags = sb->s_flags; 525 ret = affs_init_bitmap(sb, &tmp_flags); 526 if (ret) 527 return ret; 528 sb->s_flags = tmp_flags; 529 530 /* set up enough so that it can read an inode */ 531 532 root_inode = affs_iget(sb, root_block); 533 if (IS_ERR(root_inode)) 534 return PTR_ERR(root_inode); 535 536 if (affs_test_opt(AFFS_SB(sb)->s_flags, SF_INTL)) 537 sb->s_d_op = &affs_intl_dentry_operations; 538 else 539 sb->s_d_op = &affs_dentry_operations; 540 541 sb->s_root = d_make_root(root_inode); 542 if (!sb->s_root) { 543 pr_err("AFFS: Get root inode failed\n"); 544 return -ENOMEM; 545 } 546 547 sb->s_export_op = &affs_export_ops; 548 pr_debug("s_flags=%lX\n", sb->s_flags); 549 return 0; 550 } 551 552 static int 553 affs_remount(struct super_block *sb, int *flags, char *data) 554 { 555 struct affs_sb_info *sbi = AFFS_SB(sb); 556 int blocksize; 557 kuid_t uid; 558 kgid_t gid; 559 int mode; 560 int reserved; 561 int root_block; 562 unsigned long mount_flags; 563 int res = 0; 564 char volume[32]; 565 char *prefix = NULL; 566 567 pr_debug("%s(flags=0x%x,opts=\"%s\")\n", __func__, *flags, data); 568 569 sync_filesystem(sb); 570 *flags |= SB_NODIRATIME; 571 572 memcpy(volume, sbi->s_volume, 32); 573 if (!parse_options(data, &uid, &gid, &mode, &reserved, &root_block, 574 &blocksize, &prefix, volume, 575 &mount_flags)) { 576 kfree(prefix); 577 return -EINVAL; 578 } 579 580 flush_delayed_work(&sbi->sb_work); 581 582 sbi->s_flags = mount_flags; 583 sbi->s_mode = mode; 584 sbi->s_uid = uid; 585 sbi->s_gid = gid; 586 /* protect against readers */ 587 spin_lock(&sbi->symlink_lock); 588 if (prefix) { 589 kfree(sbi->s_prefix); 590 sbi->s_prefix = prefix; 591 } 592 memcpy(sbi->s_volume, volume, 32); 593 spin_unlock(&sbi->symlink_lock); 594 595 if ((bool)(*flags & SB_RDONLY) == sb_rdonly(sb)) 596 return 0; 597 598 if (*flags & SB_RDONLY) 599 affs_free_bitmap(sb); 600 else 601 res = affs_init_bitmap(sb, flags); 602 603 return res; 604 } 605 606 static int 607 affs_statfs(struct dentry *dentry, struct kstatfs *buf) 608 { 609 struct super_block *sb = dentry->d_sb; 610 int free; 611 u64 id = huge_encode_dev(sb->s_bdev->bd_dev); 612 613 pr_debug("%s() partsize=%d, reserved=%d\n", 614 __func__, AFFS_SB(sb)->s_partition_size, 615 AFFS_SB(sb)->s_reserved); 616 617 free = affs_count_free_blocks(sb); 618 buf->f_type = AFFS_SUPER_MAGIC; 619 buf->f_bsize = sb->s_blocksize; 620 buf->f_blocks = AFFS_SB(sb)->s_partition_size - AFFS_SB(sb)->s_reserved; 621 buf->f_bfree = free; 622 buf->f_bavail = free; 623 buf->f_fsid.val[0] = (u32)id; 624 buf->f_fsid.val[1] = (u32)(id >> 32); 625 buf->f_namelen = AFFSNAMEMAX; 626 return 0; 627 } 628 629 static struct dentry *affs_mount(struct file_system_type *fs_type, 630 int flags, const char *dev_name, void *data) 631 { 632 return mount_bdev(fs_type, flags, dev_name, data, affs_fill_super); 633 } 634 635 static void affs_kill_sb(struct super_block *sb) 636 { 637 struct affs_sb_info *sbi = AFFS_SB(sb); 638 kill_block_super(sb); 639 if (sbi) { 640 affs_free_bitmap(sb); 641 affs_brelse(sbi->s_root_bh); 642 kfree(sbi->s_prefix); 643 mutex_destroy(&sbi->s_bmlock); 644 kfree(sbi); 645 } 646 } 647 648 static struct file_system_type affs_fs_type = { 649 .owner = THIS_MODULE, 650 .name = "affs", 651 .mount = affs_mount, 652 .kill_sb = affs_kill_sb, 653 .fs_flags = FS_REQUIRES_DEV, 654 }; 655 MODULE_ALIAS_FS("affs"); 656 657 static int __init init_affs_fs(void) 658 { 659 int err = init_inodecache(); 660 if (err) 661 goto out1; 662 err = register_filesystem(&affs_fs_type); 663 if (err) 664 goto out; 665 return 0; 666 out: 667 destroy_inodecache(); 668 out1: 669 return err; 670 } 671 672 static void __exit exit_affs_fs(void) 673 { 674 unregister_filesystem(&affs_fs_type); 675 destroy_inodecache(); 676 } 677 678 MODULE_DESCRIPTION("Amiga filesystem support for Linux"); 679 MODULE_LICENSE("GPL"); 680 681 module_init(init_affs_fs) 682 module_exit(exit_affs_fs) 683