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 sema_init(&ei->i_link_lock, 1); 125 sema_init(&ei->i_ext_lock, 1); 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 sbi = kzalloc(sizeof(struct affs_sb_info), GFP_KERNEL); 359 if (!sbi) 360 return -ENOMEM; 361 362 sb->s_fs_info = sbi; 363 sbi->sb = sb; 364 mutex_init(&sbi->s_bmlock); 365 spin_lock_init(&sbi->symlink_lock); 366 spin_lock_init(&sbi->work_lock); 367 INIT_DELAYED_WORK(&sbi->sb_work, flush_superblock); 368 369 if (!parse_options(data,&uid,&gid,&i,&reserved,&root_block, 370 &blocksize,&sbi->s_prefix, 371 sbi->s_volume, &mount_flags)) { 372 pr_err("Error parsing options\n"); 373 return -EINVAL; 374 } 375 /* N.B. after this point s_prefix must be released */ 376 377 sbi->s_flags = mount_flags; 378 sbi->s_mode = i; 379 sbi->s_uid = uid; 380 sbi->s_gid = gid; 381 sbi->s_reserved= reserved; 382 383 /* Get the size of the device in 512-byte blocks. 384 * If we later see that the partition uses bigger 385 * blocks, we will have to change it. 386 */ 387 388 size = i_size_read(sb->s_bdev->bd_inode) >> 9; 389 pr_debug("initial blocksize=%d, #blocks=%d\n", 512, size); 390 391 affs_set_blocksize(sb, PAGE_SIZE); 392 /* Try to find root block. Its location depends on the block size. */ 393 394 i = bdev_logical_block_size(sb->s_bdev); 395 j = PAGE_SIZE; 396 if (blocksize > 0) { 397 i = j = blocksize; 398 size = size / (blocksize / 512); 399 } 400 401 for (blocksize = i; blocksize <= j; blocksize <<= 1, size >>= 1) { 402 sbi->s_root_block = root_block; 403 if (root_block < 0) 404 sbi->s_root_block = (reserved + size - 1) / 2; 405 pr_debug("setting blocksize to %d\n", blocksize); 406 affs_set_blocksize(sb, blocksize); 407 sbi->s_partition_size = size; 408 409 /* The root block location that was calculated above is not 410 * correct if the partition size is an odd number of 512- 411 * byte blocks, which will be rounded down to a number of 412 * 1024-byte blocks, and if there were an even number of 413 * reserved blocks. Ideally, all partition checkers should 414 * report the real number of blocks of the real blocksize, 415 * but since this just cannot be done, we have to try to 416 * find the root block anyways. In the above case, it is one 417 * block behind the calculated one. So we check this one, too. 418 */ 419 for (num_bm = 0; num_bm < 2; num_bm++) { 420 pr_debug("Dev %s, trying root=%u, bs=%d, " 421 "size=%d, reserved=%d\n", 422 sb->s_id, 423 sbi->s_root_block + num_bm, 424 blocksize, size, reserved); 425 root_bh = affs_bread(sb, sbi->s_root_block + num_bm); 426 if (!root_bh) 427 continue; 428 if (!affs_checksum_block(sb, root_bh) && 429 be32_to_cpu(AFFS_ROOT_HEAD(root_bh)->ptype) == T_SHORT && 430 be32_to_cpu(AFFS_ROOT_TAIL(sb, root_bh)->stype) == ST_ROOT) { 431 sbi->s_hashsize = blocksize / 4 - 56; 432 sbi->s_root_block += num_bm; 433 goto got_root; 434 } 435 affs_brelse(root_bh); 436 root_bh = NULL; 437 } 438 } 439 if (!silent) 440 pr_err("No valid root block on device %s\n", sb->s_id); 441 return -EINVAL; 442 443 /* N.B. after this point bh must be released */ 444 got_root: 445 /* Keep super block in cache */ 446 sbi->s_root_bh = root_bh; 447 root_block = sbi->s_root_block; 448 449 /* Find out which kind of FS we have */ 450 boot_bh = sb_bread(sb, 0); 451 if (!boot_bh) { 452 pr_err("Cannot read boot block\n"); 453 return -EINVAL; 454 } 455 memcpy(sig, boot_bh->b_data, 4); 456 brelse(boot_bh); 457 chksum = be32_to_cpu(*(__be32 *)sig); 458 459 /* Dircache filesystems are compatible with non-dircache ones 460 * when reading. As long as they aren't supported, writing is 461 * not recommended. 462 */ 463 if ((chksum == FS_DCFFS || chksum == MUFS_DCFFS || chksum == FS_DCOFS 464 || chksum == MUFS_DCOFS) && !sb_rdonly(sb)) { 465 pr_notice("Dircache FS - mounting %s read only\n", sb->s_id); 466 sb->s_flags |= SB_RDONLY; 467 } 468 switch (chksum) { 469 case MUFS_FS: 470 case MUFS_INTLFFS: 471 case MUFS_DCFFS: 472 affs_set_opt(sbi->s_flags, SF_MUFS); 473 /* fall thru */ 474 case FS_INTLFFS: 475 case FS_DCFFS: 476 affs_set_opt(sbi->s_flags, SF_INTL); 477 break; 478 case MUFS_FFS: 479 affs_set_opt(sbi->s_flags, SF_MUFS); 480 break; 481 case FS_FFS: 482 break; 483 case MUFS_OFS: 484 affs_set_opt(sbi->s_flags, SF_MUFS); 485 /* fall through */ 486 case FS_OFS: 487 affs_set_opt(sbi->s_flags, SF_OFS); 488 sb->s_flags |= SB_NOEXEC; 489 break; 490 case MUFS_DCOFS: 491 case MUFS_INTLOFS: 492 affs_set_opt(sbi->s_flags, SF_MUFS); 493 /* fall through */ 494 case FS_DCOFS: 495 case FS_INTLOFS: 496 affs_set_opt(sbi->s_flags, SF_INTL); 497 affs_set_opt(sbi->s_flags, SF_OFS); 498 sb->s_flags |= SB_NOEXEC; 499 break; 500 default: 501 pr_err("Unknown filesystem on device %s: %08X\n", 502 sb->s_id, chksum); 503 return -EINVAL; 504 } 505 506 if (affs_test_opt(mount_flags, SF_VERBOSE)) { 507 u8 len = AFFS_ROOT_TAIL(sb, root_bh)->disk_name[0]; 508 pr_notice("Mounting volume \"%.*s\": Type=%.3s\\%c, Blocksize=%d\n", 509 len > 31 ? 31 : len, 510 AFFS_ROOT_TAIL(sb, root_bh)->disk_name + 1, 511 sig, sig[3] + '0', blocksize); 512 } 513 514 sb->s_flags |= SB_NODEV | SB_NOSUID; 515 516 sbi->s_data_blksize = sb->s_blocksize; 517 if (affs_test_opt(sbi->s_flags, SF_OFS)) 518 sbi->s_data_blksize -= 24; 519 520 tmp_flags = sb->s_flags; 521 ret = affs_init_bitmap(sb, &tmp_flags); 522 if (ret) 523 return ret; 524 sb->s_flags = tmp_flags; 525 526 /* set up enough so that it can read an inode */ 527 528 root_inode = affs_iget(sb, root_block); 529 if (IS_ERR(root_inode)) 530 return PTR_ERR(root_inode); 531 532 if (affs_test_opt(AFFS_SB(sb)->s_flags, SF_INTL)) 533 sb->s_d_op = &affs_intl_dentry_operations; 534 else 535 sb->s_d_op = &affs_dentry_operations; 536 537 sb->s_root = d_make_root(root_inode); 538 if (!sb->s_root) { 539 pr_err("AFFS: Get root inode failed\n"); 540 return -ENOMEM; 541 } 542 543 sb->s_export_op = &affs_export_ops; 544 pr_debug("s_flags=%lX\n", sb->s_flags); 545 return 0; 546 } 547 548 static int 549 affs_remount(struct super_block *sb, int *flags, char *data) 550 { 551 struct affs_sb_info *sbi = AFFS_SB(sb); 552 int blocksize; 553 kuid_t uid; 554 kgid_t gid; 555 int mode; 556 int reserved; 557 int root_block; 558 unsigned long mount_flags; 559 int res = 0; 560 char *new_opts; 561 char volume[32]; 562 char *prefix = NULL; 563 564 new_opts = kstrdup(data, GFP_KERNEL); 565 if (data && !new_opts) 566 return -ENOMEM; 567 568 pr_debug("%s(flags=0x%x,opts=\"%s\")\n", __func__, *flags, data); 569 570 sync_filesystem(sb); 571 *flags |= SB_NODIRATIME; 572 573 memcpy(volume, sbi->s_volume, 32); 574 if (!parse_options(data, &uid, &gid, &mode, &reserved, &root_block, 575 &blocksize, &prefix, volume, 576 &mount_flags)) { 577 kfree(prefix); 578 kfree(new_opts); 579 return -EINVAL; 580 } 581 582 flush_delayed_work(&sbi->sb_work); 583 584 sbi->s_flags = mount_flags; 585 sbi->s_mode = mode; 586 sbi->s_uid = uid; 587 sbi->s_gid = gid; 588 /* protect against readers */ 589 spin_lock(&sbi->symlink_lock); 590 if (prefix) { 591 kfree(sbi->s_prefix); 592 sbi->s_prefix = prefix; 593 } 594 memcpy(sbi->s_volume, volume, 32); 595 spin_unlock(&sbi->symlink_lock); 596 597 if ((bool)(*flags & SB_RDONLY) == sb_rdonly(sb)) 598 return 0; 599 600 if (*flags & SB_RDONLY) 601 affs_free_bitmap(sb); 602 else 603 res = affs_init_bitmap(sb, flags); 604 605 return res; 606 } 607 608 static int 609 affs_statfs(struct dentry *dentry, struct kstatfs *buf) 610 { 611 struct super_block *sb = dentry->d_sb; 612 int free; 613 u64 id = huge_encode_dev(sb->s_bdev->bd_dev); 614 615 pr_debug("%s() partsize=%d, reserved=%d\n", 616 __func__, AFFS_SB(sb)->s_partition_size, 617 AFFS_SB(sb)->s_reserved); 618 619 free = affs_count_free_blocks(sb); 620 buf->f_type = AFFS_SUPER_MAGIC; 621 buf->f_bsize = sb->s_blocksize; 622 buf->f_blocks = AFFS_SB(sb)->s_partition_size - AFFS_SB(sb)->s_reserved; 623 buf->f_bfree = free; 624 buf->f_bavail = free; 625 buf->f_fsid.val[0] = (u32)id; 626 buf->f_fsid.val[1] = (u32)(id >> 32); 627 buf->f_namelen = AFFSNAMEMAX; 628 return 0; 629 } 630 631 static struct dentry *affs_mount(struct file_system_type *fs_type, 632 int flags, const char *dev_name, void *data) 633 { 634 return mount_bdev(fs_type, flags, dev_name, data, affs_fill_super); 635 } 636 637 static void affs_kill_sb(struct super_block *sb) 638 { 639 struct affs_sb_info *sbi = AFFS_SB(sb); 640 kill_block_super(sb); 641 if (sbi) { 642 affs_free_bitmap(sb); 643 affs_brelse(sbi->s_root_bh); 644 kfree(sbi->s_prefix); 645 mutex_destroy(&sbi->s_bmlock); 646 kfree(sbi); 647 } 648 } 649 650 static struct file_system_type affs_fs_type = { 651 .owner = THIS_MODULE, 652 .name = "affs", 653 .mount = affs_mount, 654 .kill_sb = affs_kill_sb, 655 .fs_flags = FS_REQUIRES_DEV, 656 }; 657 MODULE_ALIAS_FS("affs"); 658 659 static int __init init_affs_fs(void) 660 { 661 int err = init_inodecache(); 662 if (err) 663 goto out1; 664 err = register_filesystem(&affs_fs_type); 665 if (err) 666 goto out; 667 return 0; 668 out: 669 destroy_inodecache(); 670 out1: 671 return err; 672 } 673 674 static void __exit exit_affs_fs(void) 675 { 676 unregister_filesystem(&affs_fs_type); 677 destroy_inodecache(); 678 } 679 680 MODULE_DESCRIPTION("Amiga filesystem support for Linux"); 681 MODULE_LICENSE("GPL"); 682 683 module_init(init_affs_fs) 684 module_exit(exit_affs_fs) 685