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 <linux/seq_file.h> 24 #include "affs.h" 25 26 static int affs_statfs(struct dentry *dentry, struct kstatfs *buf); 27 static int affs_show_options(struct seq_file *m, struct dentry *root); 28 static int affs_remount (struct super_block *sb, int *flags, char *data); 29 30 static void 31 affs_commit_super(struct super_block *sb, int wait) 32 { 33 struct affs_sb_info *sbi = AFFS_SB(sb); 34 struct buffer_head *bh = sbi->s_root_bh; 35 struct affs_root_tail *tail = AFFS_ROOT_TAIL(sb, bh); 36 37 lock_buffer(bh); 38 affs_secs_to_datestamp(ktime_get_real_seconds(), &tail->disk_change); 39 affs_fix_checksum(sb, bh); 40 unlock_buffer(bh); 41 42 mark_buffer_dirty(bh); 43 if (wait) 44 sync_dirty_buffer(bh); 45 } 46 47 static void 48 affs_put_super(struct super_block *sb) 49 { 50 struct affs_sb_info *sbi = AFFS_SB(sb); 51 pr_debug("%s()\n", __func__); 52 53 cancel_delayed_work_sync(&sbi->sb_work); 54 } 55 56 static int 57 affs_sync_fs(struct super_block *sb, int wait) 58 { 59 affs_commit_super(sb, wait); 60 return 0; 61 } 62 63 static void flush_superblock(struct work_struct *work) 64 { 65 struct affs_sb_info *sbi; 66 struct super_block *sb; 67 68 sbi = container_of(work, struct affs_sb_info, sb_work.work); 69 sb = sbi->sb; 70 71 spin_lock(&sbi->work_lock); 72 sbi->work_queued = 0; 73 spin_unlock(&sbi->work_lock); 74 75 affs_commit_super(sb, 1); 76 } 77 78 void affs_mark_sb_dirty(struct super_block *sb) 79 { 80 struct affs_sb_info *sbi = AFFS_SB(sb); 81 unsigned long delay; 82 83 if (sb_rdonly(sb)) 84 return; 85 86 spin_lock(&sbi->work_lock); 87 if (!sbi->work_queued) { 88 delay = msecs_to_jiffies(dirty_writeback_interval * 10); 89 queue_delayed_work(system_long_wq, &sbi->sb_work, delay); 90 sbi->work_queued = 1; 91 } 92 spin_unlock(&sbi->work_lock); 93 } 94 95 static struct kmem_cache * affs_inode_cachep; 96 97 static struct inode *affs_alloc_inode(struct super_block *sb) 98 { 99 struct affs_inode_info *i; 100 101 i = kmem_cache_alloc(affs_inode_cachep, GFP_KERNEL); 102 if (!i) 103 return NULL; 104 105 i->vfs_inode.i_version = 1; 106 i->i_lc = NULL; 107 i->i_ext_bh = NULL; 108 i->i_pa_cnt = 0; 109 110 return &i->vfs_inode; 111 } 112 113 static void affs_i_callback(struct rcu_head *head) 114 { 115 struct inode *inode = container_of(head, struct inode, i_rcu); 116 kmem_cache_free(affs_inode_cachep, AFFS_I(inode)); 117 } 118 119 static void affs_destroy_inode(struct inode *inode) 120 { 121 call_rcu(&inode->i_rcu, affs_i_callback); 122 } 123 124 static void init_once(void *foo) 125 { 126 struct affs_inode_info *ei = (struct affs_inode_info *) foo; 127 128 sema_init(&ei->i_link_lock, 1); 129 sema_init(&ei->i_ext_lock, 1); 130 inode_init_once(&ei->vfs_inode); 131 } 132 133 static int __init init_inodecache(void) 134 { 135 affs_inode_cachep = kmem_cache_create("affs_inode_cache", 136 sizeof(struct affs_inode_info), 137 0, (SLAB_RECLAIM_ACCOUNT| 138 SLAB_MEM_SPREAD|SLAB_ACCOUNT), 139 init_once); 140 if (affs_inode_cachep == NULL) 141 return -ENOMEM; 142 return 0; 143 } 144 145 static void destroy_inodecache(void) 146 { 147 /* 148 * Make sure all delayed rcu free inodes are flushed before we 149 * destroy cache. 150 */ 151 rcu_barrier(); 152 kmem_cache_destroy(affs_inode_cachep); 153 } 154 155 static const struct super_operations affs_sops = { 156 .alloc_inode = affs_alloc_inode, 157 .destroy_inode = affs_destroy_inode, 158 .write_inode = affs_write_inode, 159 .evict_inode = affs_evict_inode, 160 .put_super = affs_put_super, 161 .sync_fs = affs_sync_fs, 162 .statfs = affs_statfs, 163 .remount_fs = affs_remount, 164 .show_options = affs_show_options, 165 }; 166 167 enum { 168 Opt_bs, Opt_mode, Opt_mufs, Opt_notruncate, Opt_prefix, Opt_protect, 169 Opt_reserved, Opt_root, Opt_setgid, Opt_setuid, 170 Opt_verbose, Opt_volume, Opt_ignore, Opt_err, 171 }; 172 173 static const match_table_t tokens = { 174 {Opt_bs, "bs=%u"}, 175 {Opt_mode, "mode=%o"}, 176 {Opt_mufs, "mufs"}, 177 {Opt_notruncate, "nofilenametruncate"}, 178 {Opt_prefix, "prefix=%s"}, 179 {Opt_protect, "protect"}, 180 {Opt_reserved, "reserved=%u"}, 181 {Opt_root, "root=%u"}, 182 {Opt_setgid, "setgid=%u"}, 183 {Opt_setuid, "setuid=%u"}, 184 {Opt_verbose, "verbose"}, 185 {Opt_volume, "volume=%s"}, 186 {Opt_ignore, "grpquota"}, 187 {Opt_ignore, "noquota"}, 188 {Opt_ignore, "quota"}, 189 {Opt_ignore, "usrquota"}, 190 {Opt_err, NULL}, 191 }; 192 193 static int 194 parse_options(char *options, kuid_t *uid, kgid_t *gid, int *mode, int *reserved, s32 *root, 195 int *blocksize, char **prefix, char *volume, unsigned long *mount_opts) 196 { 197 char *p; 198 substring_t args[MAX_OPT_ARGS]; 199 200 /* Fill in defaults */ 201 202 *uid = current_uid(); 203 *gid = current_gid(); 204 *reserved = 2; 205 *root = -1; 206 *blocksize = -1; 207 volume[0] = ':'; 208 volume[1] = 0; 209 *mount_opts = 0; 210 if (!options) 211 return 1; 212 213 while ((p = strsep(&options, ",")) != NULL) { 214 int token, n, option; 215 if (!*p) 216 continue; 217 218 token = match_token(p, tokens, args); 219 switch (token) { 220 case Opt_bs: 221 if (match_int(&args[0], &n)) 222 return 0; 223 if (n != 512 && n != 1024 && n != 2048 224 && n != 4096) { 225 pr_warn("Invalid blocksize (512, 1024, 2048, 4096 allowed)\n"); 226 return 0; 227 } 228 *blocksize = n; 229 break; 230 case Opt_mode: 231 if (match_octal(&args[0], &option)) 232 return 0; 233 *mode = option & 0777; 234 affs_set_opt(*mount_opts, SF_SETMODE); 235 break; 236 case Opt_mufs: 237 affs_set_opt(*mount_opts, SF_MUFS); 238 break; 239 case Opt_notruncate: 240 affs_set_opt(*mount_opts, SF_NO_TRUNCATE); 241 break; 242 case Opt_prefix: 243 *prefix = match_strdup(&args[0]); 244 if (!*prefix) 245 return 0; 246 affs_set_opt(*mount_opts, SF_PREFIX); 247 break; 248 case Opt_protect: 249 affs_set_opt(*mount_opts, SF_IMMUTABLE); 250 break; 251 case Opt_reserved: 252 if (match_int(&args[0], reserved)) 253 return 0; 254 break; 255 case Opt_root: 256 if (match_int(&args[0], root)) 257 return 0; 258 break; 259 case Opt_setgid: 260 if (match_int(&args[0], &option)) 261 return 0; 262 *gid = make_kgid(current_user_ns(), option); 263 if (!gid_valid(*gid)) 264 return 0; 265 affs_set_opt(*mount_opts, SF_SETGID); 266 break; 267 case Opt_setuid: 268 if (match_int(&args[0], &option)) 269 return 0; 270 *uid = make_kuid(current_user_ns(), option); 271 if (!uid_valid(*uid)) 272 return 0; 273 affs_set_opt(*mount_opts, SF_SETUID); 274 break; 275 case Opt_verbose: 276 affs_set_opt(*mount_opts, SF_VERBOSE); 277 break; 278 case Opt_volume: { 279 char *vol = match_strdup(&args[0]); 280 if (!vol) 281 return 0; 282 strlcpy(volume, vol, 32); 283 kfree(vol); 284 break; 285 } 286 case Opt_ignore: 287 /* Silently ignore the quota options */ 288 break; 289 default: 290 pr_warn("Unrecognized mount option \"%s\" or missing value\n", 291 p); 292 return 0; 293 } 294 } 295 return 1; 296 } 297 298 static int affs_show_options(struct seq_file *m, struct dentry *root) 299 { 300 struct super_block *sb = root->d_sb; 301 struct affs_sb_info *sbi = AFFS_SB(sb); 302 303 if (sb->s_blocksize) 304 seq_printf(m, ",bs=%lu", sb->s_blocksize); 305 if (affs_test_opt(sbi->s_flags, SF_SETMODE)) 306 seq_printf(m, ",mode=%o", sbi->s_mode); 307 if (affs_test_opt(sbi->s_flags, SF_MUFS)) 308 seq_puts(m, ",mufs"); 309 if (affs_test_opt(sbi->s_flags, SF_NO_TRUNCATE)) 310 seq_puts(m, ",nofilenametruncate"); 311 if (affs_test_opt(sbi->s_flags, SF_PREFIX)) 312 seq_printf(m, ",prefix=%s", sbi->s_prefix); 313 if (affs_test_opt(sbi->s_flags, SF_IMMUTABLE)) 314 seq_puts(m, ",protect"); 315 if (sbi->s_reserved != 2) 316 seq_printf(m, ",reserved=%u", sbi->s_reserved); 317 if (sbi->s_root_block != (sbi->s_reserved + sbi->s_partition_size - 1) / 2) 318 seq_printf(m, ",root=%u", sbi->s_root_block); 319 if (affs_test_opt(sbi->s_flags, SF_SETGID)) 320 seq_printf(m, ",setgid=%u", 321 from_kgid_munged(&init_user_ns, sbi->s_gid)); 322 if (affs_test_opt(sbi->s_flags, SF_SETUID)) 323 seq_printf(m, ",setuid=%u", 324 from_kuid_munged(&init_user_ns, sbi->s_uid)); 325 if (affs_test_opt(sbi->s_flags, SF_VERBOSE)) 326 seq_puts(m, ",verbose"); 327 if (sbi->s_volume[0]) 328 seq_printf(m, ",volume=%s", sbi->s_volume); 329 return 0; 330 } 331 332 /* This function definitely needs to be split up. Some fine day I'll 333 * hopefully have the guts to do so. Until then: sorry for the mess. 334 */ 335 336 static int affs_fill_super(struct super_block *sb, void *data, int silent) 337 { 338 struct affs_sb_info *sbi; 339 struct buffer_head *root_bh = NULL; 340 struct buffer_head *boot_bh; 341 struct inode *root_inode = NULL; 342 s32 root_block; 343 int size, blocksize; 344 u32 chksum; 345 int num_bm; 346 int i, j; 347 kuid_t uid; 348 kgid_t gid; 349 int reserved; 350 unsigned long mount_flags; 351 int tmp_flags; /* fix remount prototype... */ 352 u8 sig[4]; 353 int ret; 354 355 pr_debug("read_super(%s)\n", data ? (const char *)data : "no options"); 356 357 sb->s_magic = AFFS_SUPER_MAGIC; 358 sb->s_op = &affs_sops; 359 sb->s_flags |= MS_NODIRATIME; 360 361 sbi = kzalloc(sizeof(struct affs_sb_info), GFP_KERNEL); 362 if (!sbi) 363 return -ENOMEM; 364 365 sb->s_fs_info = sbi; 366 sbi->sb = sb; 367 mutex_init(&sbi->s_bmlock); 368 spin_lock_init(&sbi->symlink_lock); 369 spin_lock_init(&sbi->work_lock); 370 INIT_DELAYED_WORK(&sbi->sb_work, flush_superblock); 371 372 if (!parse_options(data,&uid,&gid,&i,&reserved,&root_block, 373 &blocksize,&sbi->s_prefix, 374 sbi->s_volume, &mount_flags)) { 375 pr_err("Error parsing options\n"); 376 return -EINVAL; 377 } 378 /* N.B. after this point s_prefix must be released */ 379 380 sbi->s_flags = mount_flags; 381 sbi->s_mode = i; 382 sbi->s_uid = uid; 383 sbi->s_gid = gid; 384 sbi->s_reserved= reserved; 385 386 /* Get the size of the device in 512-byte blocks. 387 * If we later see that the partition uses bigger 388 * blocks, we will have to change it. 389 */ 390 391 size = i_size_read(sb->s_bdev->bd_inode) >> 9; 392 pr_debug("initial blocksize=%d, #blocks=%d\n", 512, size); 393 394 affs_set_blocksize(sb, PAGE_SIZE); 395 /* Try to find root block. Its location depends on the block size. */ 396 397 i = bdev_logical_block_size(sb->s_bdev); 398 j = PAGE_SIZE; 399 if (blocksize > 0) { 400 i = j = blocksize; 401 size = size / (blocksize / 512); 402 } 403 404 for (blocksize = i; blocksize <= j; blocksize <<= 1, size >>= 1) { 405 sbi->s_root_block = root_block; 406 if (root_block < 0) 407 sbi->s_root_block = (reserved + size - 1) / 2; 408 pr_debug("setting blocksize to %d\n", blocksize); 409 affs_set_blocksize(sb, blocksize); 410 sbi->s_partition_size = size; 411 412 /* The root block location that was calculated above is not 413 * correct if the partition size is an odd number of 512- 414 * byte blocks, which will be rounded down to a number of 415 * 1024-byte blocks, and if there were an even number of 416 * reserved blocks. Ideally, all partition checkers should 417 * report the real number of blocks of the real blocksize, 418 * but since this just cannot be done, we have to try to 419 * find the root block anyways. In the above case, it is one 420 * block behind the calculated one. So we check this one, too. 421 */ 422 for (num_bm = 0; num_bm < 2; num_bm++) { 423 pr_debug("Dev %s, trying root=%u, bs=%d, " 424 "size=%d, reserved=%d\n", 425 sb->s_id, 426 sbi->s_root_block + num_bm, 427 blocksize, size, reserved); 428 root_bh = affs_bread(sb, sbi->s_root_block + num_bm); 429 if (!root_bh) 430 continue; 431 if (!affs_checksum_block(sb, root_bh) && 432 be32_to_cpu(AFFS_ROOT_HEAD(root_bh)->ptype) == T_SHORT && 433 be32_to_cpu(AFFS_ROOT_TAIL(sb, root_bh)->stype) == ST_ROOT) { 434 sbi->s_hashsize = blocksize / 4 - 56; 435 sbi->s_root_block += num_bm; 436 goto got_root; 437 } 438 affs_brelse(root_bh); 439 root_bh = NULL; 440 } 441 } 442 if (!silent) 443 pr_err("No valid root block on device %s\n", sb->s_id); 444 return -EINVAL; 445 446 /* N.B. after this point bh must be released */ 447 got_root: 448 /* Keep super block in cache */ 449 sbi->s_root_bh = root_bh; 450 root_block = sbi->s_root_block; 451 452 /* Find out which kind of FS we have */ 453 boot_bh = sb_bread(sb, 0); 454 if (!boot_bh) { 455 pr_err("Cannot read boot block\n"); 456 return -EINVAL; 457 } 458 memcpy(sig, boot_bh->b_data, 4); 459 brelse(boot_bh); 460 chksum = be32_to_cpu(*(__be32 *)sig); 461 462 /* Dircache filesystems are compatible with non-dircache ones 463 * when reading. As long as they aren't supported, writing is 464 * not recommended. 465 */ 466 if ((chksum == FS_DCFFS || chksum == MUFS_DCFFS || chksum == FS_DCOFS 467 || chksum == MUFS_DCOFS) && !sb_rdonly(sb)) { 468 pr_notice("Dircache FS - mounting %s read only\n", sb->s_id); 469 sb->s_flags |= MS_RDONLY; 470 } 471 switch (chksum) { 472 case MUFS_FS: 473 case MUFS_INTLFFS: 474 case MUFS_DCFFS: 475 affs_set_opt(sbi->s_flags, SF_MUFS); 476 /* fall thru */ 477 case FS_INTLFFS: 478 case FS_DCFFS: 479 affs_set_opt(sbi->s_flags, SF_INTL); 480 break; 481 case MUFS_FFS: 482 affs_set_opt(sbi->s_flags, SF_MUFS); 483 break; 484 case FS_FFS: 485 break; 486 case MUFS_OFS: 487 affs_set_opt(sbi->s_flags, SF_MUFS); 488 /* fall thru */ 489 case FS_OFS: 490 affs_set_opt(sbi->s_flags, SF_OFS); 491 sb->s_flags |= MS_NOEXEC; 492 break; 493 case MUFS_DCOFS: 494 case MUFS_INTLOFS: 495 affs_set_opt(sbi->s_flags, SF_MUFS); 496 case FS_DCOFS: 497 case FS_INTLOFS: 498 affs_set_opt(sbi->s_flags, SF_INTL); 499 affs_set_opt(sbi->s_flags, SF_OFS); 500 sb->s_flags |= MS_NOEXEC; 501 break; 502 default: 503 pr_err("Unknown filesystem on device %s: %08X\n", 504 sb->s_id, chksum); 505 return -EINVAL; 506 } 507 508 if (affs_test_opt(mount_flags, SF_VERBOSE)) { 509 u8 len = AFFS_ROOT_TAIL(sb, root_bh)->disk_name[0]; 510 pr_notice("Mounting volume \"%.*s\": Type=%.3s\\%c, Blocksize=%d\n", 511 len > 31 ? 31 : len, 512 AFFS_ROOT_TAIL(sb, root_bh)->disk_name + 1, 513 sig, sig[3] + '0', blocksize); 514 } 515 516 sb->s_flags |= MS_NODEV | MS_NOSUID; 517 518 sbi->s_data_blksize = sb->s_blocksize; 519 if (affs_test_opt(sbi->s_flags, SF_OFS)) 520 sbi->s_data_blksize -= 24; 521 522 tmp_flags = sb->s_flags; 523 ret = affs_init_bitmap(sb, &tmp_flags); 524 if (ret) 525 return ret; 526 sb->s_flags = tmp_flags; 527 528 /* set up enough so that it can read an inode */ 529 530 root_inode = affs_iget(sb, root_block); 531 if (IS_ERR(root_inode)) 532 return PTR_ERR(root_inode); 533 534 if (affs_test_opt(AFFS_SB(sb)->s_flags, SF_INTL)) 535 sb->s_d_op = &affs_intl_dentry_operations; 536 else 537 sb->s_d_op = &affs_dentry_operations; 538 539 sb->s_root = d_make_root(root_inode); 540 if (!sb->s_root) { 541 pr_err("AFFS: Get root inode failed\n"); 542 return -ENOMEM; 543 } 544 545 sb->s_export_op = &affs_export_ops; 546 pr_debug("s_flags=%lX\n", sb->s_flags); 547 return 0; 548 } 549 550 static int 551 affs_remount(struct super_block *sb, int *flags, char *data) 552 { 553 struct affs_sb_info *sbi = AFFS_SB(sb); 554 int blocksize; 555 kuid_t uid; 556 kgid_t gid; 557 int mode; 558 int reserved; 559 int root_block; 560 unsigned long mount_flags; 561 int res = 0; 562 char *new_opts; 563 char volume[32]; 564 char *prefix = NULL; 565 566 new_opts = kstrdup(data, GFP_KERNEL); 567 if (data && !new_opts) 568 return -ENOMEM; 569 570 pr_debug("%s(flags=0x%x,opts=\"%s\")\n", __func__, *flags, data); 571 572 sync_filesystem(sb); 573 *flags |= MS_NODIRATIME; 574 575 memcpy(volume, sbi->s_volume, 32); 576 if (!parse_options(data, &uid, &gid, &mode, &reserved, &root_block, 577 &blocksize, &prefix, volume, 578 &mount_flags)) { 579 kfree(prefix); 580 kfree(new_opts); 581 return -EINVAL; 582 } 583 584 flush_delayed_work(&sbi->sb_work); 585 586 sbi->s_flags = mount_flags; 587 sbi->s_mode = mode; 588 sbi->s_uid = uid; 589 sbi->s_gid = gid; 590 /* protect against readers */ 591 spin_lock(&sbi->symlink_lock); 592 if (prefix) { 593 kfree(sbi->s_prefix); 594 sbi->s_prefix = prefix; 595 } 596 memcpy(sbi->s_volume, volume, 32); 597 spin_unlock(&sbi->symlink_lock); 598 599 if ((bool)(*flags & MS_RDONLY) == sb_rdonly(sb)) 600 return 0; 601 602 if (*flags & MS_RDONLY) 603 affs_free_bitmap(sb); 604 else 605 res = affs_init_bitmap(sb, flags); 606 607 return res; 608 } 609 610 static int 611 affs_statfs(struct dentry *dentry, struct kstatfs *buf) 612 { 613 struct super_block *sb = dentry->d_sb; 614 int free; 615 u64 id = huge_encode_dev(sb->s_bdev->bd_dev); 616 617 pr_debug("%s() partsize=%d, reserved=%d\n", 618 __func__, AFFS_SB(sb)->s_partition_size, 619 AFFS_SB(sb)->s_reserved); 620 621 free = affs_count_free_blocks(sb); 622 buf->f_type = AFFS_SUPER_MAGIC; 623 buf->f_bsize = sb->s_blocksize; 624 buf->f_blocks = AFFS_SB(sb)->s_partition_size - AFFS_SB(sb)->s_reserved; 625 buf->f_bfree = free; 626 buf->f_bavail = free; 627 buf->f_fsid.val[0] = (u32)id; 628 buf->f_fsid.val[1] = (u32)(id >> 32); 629 buf->f_namelen = AFFSNAMEMAX; 630 return 0; 631 } 632 633 static struct dentry *affs_mount(struct file_system_type *fs_type, 634 int flags, const char *dev_name, void *data) 635 { 636 return mount_bdev(fs_type, flags, dev_name, data, affs_fill_super); 637 } 638 639 static void affs_kill_sb(struct super_block *sb) 640 { 641 struct affs_sb_info *sbi = AFFS_SB(sb); 642 kill_block_super(sb); 643 if (sbi) { 644 affs_free_bitmap(sb); 645 affs_brelse(sbi->s_root_bh); 646 kfree(sbi->s_prefix); 647 mutex_destroy(&sbi->s_bmlock); 648 kfree(sbi); 649 } 650 } 651 652 static struct file_system_type affs_fs_type = { 653 .owner = THIS_MODULE, 654 .name = "affs", 655 .mount = affs_mount, 656 .kill_sb = affs_kill_sb, 657 .fs_flags = FS_REQUIRES_DEV, 658 }; 659 MODULE_ALIAS_FS("affs"); 660 661 static int __init init_affs_fs(void) 662 { 663 int err = init_inodecache(); 664 if (err) 665 goto out1; 666 err = register_filesystem(&affs_fs_type); 667 if (err) 668 goto out; 669 return 0; 670 out: 671 destroy_inodecache(); 672 out1: 673 return err; 674 } 675 676 static void __exit exit_affs_fs(void) 677 { 678 unregister_filesystem(&affs_fs_type); 679 destroy_inodecache(); 680 } 681 682 MODULE_DESCRIPTION("Amiga filesystem support for Linux"); 683 MODULE_LICENSE("GPL"); 684 685 module_init(init_affs_fs) 686 module_exit(exit_affs_fs) 687