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 28static int affs_statfs(struct dentry *dentry, struct kstatfs *buf); 29static int affs_show_options(struct seq_file *m, struct dentry *root); 30static int affs_remount (struct super_block *sb, int *flags, char *data); 31 32static void 33affs_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 49static void 50affs_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 58static int 59affs_sync_fs(struct super_block *sb, int wait) 60{ 61 affs_commit_super(sb, wait); 62 return 0; 63} 64 65static 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 80void 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 97static struct kmem_cache * affs_inode_cachep; 98 99static struct inode *affs_alloc_inode(struct super_block *sb) 100{ 101 struct affs_inode_info *i; 102 103 i = alloc_inode_sb(sb, 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 115static void affs_free_inode(struct inode *inode) 116{ 117 kmem_cache_free(affs_inode_cachep, AFFS_I(inode)); 118} 119 120static 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 129static 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 | SLAB_ACCOUNT), 134 init_once); 135 if (affs_inode_cachep == NULL) 136 return -ENOMEM; 137 return 0; 138} 139 140static void destroy_inodecache(void) 141{ 142 /* 143 * Make sure all delayed rcu free inodes are flushed before we 144 * destroy cache. 145 */ 146 rcu_barrier(); 147 kmem_cache_destroy(affs_inode_cachep); 148} 149 150static const struct super_operations affs_sops = { 151 .alloc_inode = affs_alloc_inode, 152 .free_inode = affs_free_inode, 153 .write_inode = affs_write_inode, 154 .evict_inode = affs_evict_inode, 155 .put_super = affs_put_super, 156 .sync_fs = affs_sync_fs, 157 .statfs = affs_statfs, 158 .remount_fs = affs_remount, 159 .show_options = affs_show_options, 160}; 161 162enum { 163 Opt_bs, Opt_mode, Opt_mufs, Opt_notruncate, Opt_prefix, Opt_protect, 164 Opt_reserved, Opt_root, Opt_setgid, Opt_setuid, 165 Opt_verbose, Opt_volume, Opt_ignore, Opt_err, 166}; 167 168static const match_table_t tokens = { 169 {Opt_bs, "bs=%u"}, 170 {Opt_mode, "mode=%o"}, 171 {Opt_mufs, "mufs"}, 172 {Opt_notruncate, "nofilenametruncate"}, 173 {Opt_prefix, "prefix=%s"}, 174 {Opt_protect, "protect"}, 175 {Opt_reserved, "reserved=%u"}, 176 {Opt_root, "root=%u"}, 177 {Opt_setgid, "setgid=%u"}, 178 {Opt_setuid, "setuid=%u"}, 179 {Opt_verbose, "verbose"}, 180 {Opt_volume, "volume=%s"}, 181 {Opt_ignore, "grpquota"}, 182 {Opt_ignore, "noquota"}, 183 {Opt_ignore, "quota"}, 184 {Opt_ignore, "usrquota"}, 185 {Opt_err, NULL}, 186}; 187 188static int 189parse_options(char *options, kuid_t *uid, kgid_t *gid, int *mode, int *reserved, s32 *root, 190 int *blocksize, char **prefix, char *volume, unsigned long *mount_opts) 191{ 192 char *p; 193 substring_t args[MAX_OPT_ARGS]; 194 195 /* Fill in defaults */ 196 197 *uid = current_uid(); 198 *gid = current_gid(); 199 *reserved = 2; 200 *root = -1; 201 *blocksize = -1; 202 volume[0] = ':'; 203 volume[1] = 0; 204 *mount_opts = 0; 205 if (!options) 206 return 1; 207 208 while ((p = strsep(&options, ",")) != NULL) { 209 int token, n, option; 210 if (!*p) 211 continue; 212 213 token = match_token(p, tokens, args); 214 switch (token) { 215 case Opt_bs: 216 if (match_int(&args[0], &n)) 217 return 0; 218 if (n != 512 && n != 1024 && n != 2048 219 && n != 4096) { 220 pr_warn("Invalid blocksize (512, 1024, 2048, 4096 allowed)\n"); 221 return 0; 222 } 223 *blocksize = n; 224 break; 225 case Opt_mode: 226 if (match_octal(&args[0], &option)) 227 return 0; 228 *mode = option & 0777; 229 affs_set_opt(*mount_opts, SF_SETMODE); 230 break; 231 case Opt_mufs: 232 affs_set_opt(*mount_opts, SF_MUFS); 233 break; 234 case Opt_notruncate: 235 affs_set_opt(*mount_opts, SF_NO_TRUNCATE); 236 break; 237 case Opt_prefix: 238 kfree(*prefix); 239 *prefix = match_strdup(&args[0]); 240 if (!*prefix) 241 return 0; 242 affs_set_opt(*mount_opts, SF_PREFIX); 243 break; 244 case Opt_protect: 245 affs_set_opt(*mount_opts, SF_IMMUTABLE); 246 break; 247 case Opt_reserved: 248 if (match_int(&args[0], reserved)) 249 return 0; 250 break; 251 case Opt_root: 252 if (match_int(&args[0], root)) 253 return 0; 254 break; 255 case Opt_setgid: 256 if (match_int(&args[0], &option)) 257 return 0; 258 *gid = make_kgid(current_user_ns(), option); 259 if (!gid_valid(*gid)) 260 return 0; 261 affs_set_opt(*mount_opts, SF_SETGID); 262 break; 263 case Opt_setuid: 264 if (match_int(&args[0], &option)) 265 return 0; 266 *uid = make_kuid(current_user_ns(), option); 267 if (!uid_valid(*uid)) 268 return 0; 269 affs_set_opt(*mount_opts, SF_SETUID); 270 break; 271 case Opt_verbose: 272 affs_set_opt(*mount_opts, SF_VERBOSE); 273 break; 274 case Opt_volume: { 275 char *vol = match_strdup(&args[0]); 276 if (!vol) 277 return 0; 278 strscpy(volume, vol, 32); 279 kfree(vol); 280 break; 281 } 282 case Opt_ignore: 283 /* Silently ignore the quota options */ 284 break; 285 default: 286 pr_warn("Unrecognized mount option \"%s\" or missing value\n", 287 p); 288 return 0; 289 } 290 } 291 return 1; 292} 293 294static int affs_show_options(struct seq_file *m, struct dentry *root) 295{ 296 struct super_block *sb = root->d_sb; 297 struct affs_sb_info *sbi = AFFS_SB(sb); 298 299 if (sb->s_blocksize) 300 seq_printf(m, ",bs=%lu", sb->s_blocksize); 301 if (affs_test_opt(sbi->s_flags, SF_SETMODE)) 302 seq_printf(m, ",mode=%o", sbi->s_mode); 303 if (affs_test_opt(sbi->s_flags, SF_MUFS)) 304 seq_puts(m, ",mufs"); 305 if (affs_test_opt(sbi->s_flags, SF_NO_TRUNCATE)) 306 seq_puts(m, ",nofilenametruncate"); 307 if (affs_test_opt(sbi->s_flags, SF_PREFIX)) 308 seq_printf(m, ",prefix=%s", sbi->s_prefix); 309 if (affs_test_opt(sbi->s_flags, SF_IMMUTABLE)) 310 seq_puts(m, ",protect"); 311 if (sbi->s_reserved != 2) 312 seq_printf(m, ",reserved=%u", sbi->s_reserved); 313 if (sbi->s_root_block != (sbi->s_reserved + sbi->s_partition_size - 1) / 2) 314 seq_printf(m, ",root=%u", sbi->s_root_block); 315 if (affs_test_opt(sbi->s_flags, SF_SETGID)) 316 seq_printf(m, ",setgid=%u", 317 from_kgid_munged(&init_user_ns, sbi->s_gid)); 318 if (affs_test_opt(sbi->s_flags, SF_SETUID)) 319 seq_printf(m, ",setuid=%u", 320 from_kuid_munged(&init_user_ns, sbi->s_uid)); 321 if (affs_test_opt(sbi->s_flags, SF_VERBOSE)) 322 seq_puts(m, ",verbose"); 323 if (sbi->s_volume[0]) 324 seq_printf(m, ",volume=%s", sbi->s_volume); 325 return 0; 326} 327 328/* This function definitely needs to be split up. Some fine day I'll 329 * hopefully have the guts to do so. Until then: sorry for the mess. 330 */ 331 332static int affs_fill_super(struct super_block *sb, void *data, int silent) 333{ 334 struct affs_sb_info *sbi; 335 struct buffer_head *root_bh = NULL; 336 struct buffer_head *boot_bh; 337 struct inode *root_inode = NULL; 338 s32 root_block; 339 int size, blocksize; 340 u32 chksum; 341 int num_bm; 342 int i, j; 343 kuid_t uid; 344 kgid_t gid; 345 int reserved; 346 unsigned long mount_flags; 347 int tmp_flags; /* fix remount prototype... */ 348 u8 sig[4]; 349 int ret; 350 351 pr_debug("read_super(%s)\n", data ? (const char *)data : "no options"); 352 353 sb->s_magic = AFFS_SUPER_MAGIC; 354 sb->s_op = &affs_sops; 355 sb->s_flags |= SB_NODIRATIME; 356 357 sb->s_time_gran = NSEC_PER_SEC; 358 sb->s_time_min = sys_tz.tz_minuteswest * 60 + AFFS_EPOCH_DELTA; 359 sb->s_time_max = 86400LL * U32_MAX + 86400 + sb->s_time_min; 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 = bdev_nr_sectors(sb->s_bdev); 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 */ 447got_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 |= SB_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 fallthrough; 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 fallthrough; 489 case FS_OFS: 490 affs_set_opt(sbi->s_flags, SF_OFS); 491 sb->s_flags |= SB_NOEXEC; 492 break; 493 case MUFS_DCOFS: 494 case MUFS_INTLOFS: 495 affs_set_opt(sbi->s_flags, SF_MUFS); 496 fallthrough; 497 case FS_DCOFS: 498 case FS_INTLOFS: 499 affs_set_opt(sbi->s_flags, SF_INTL); 500 affs_set_opt(sbi->s_flags, SF_OFS); 501 sb->s_flags |= SB_NOEXEC; 502 break; 503 default: 504 pr_err("Unknown filesystem on device %s: %08X\n", 505 sb->s_id, chksum); 506 return -EINVAL; 507 } 508 509 if (affs_test_opt(mount_flags, SF_VERBOSE)) { 510 u8 len = AFFS_ROOT_TAIL(sb, root_bh)->disk_name[0]; 511 pr_notice("Mounting volume \"%.*s\": Type=%.3s\\%c, Blocksize=%d\n", 512 len > 31 ? 31 : len, 513 AFFS_ROOT_TAIL(sb, root_bh)->disk_name + 1, 514 sig, sig[3] + '0', blocksize); 515 } 516 517 sb->s_flags |= SB_NODEV | SB_NOSUID; 518 519 sbi->s_data_blksize = sb->s_blocksize; 520 if (affs_test_opt(sbi->s_flags, SF_OFS)) 521 sbi->s_data_blksize -= 24; 522 523 tmp_flags = sb->s_flags; 524 ret = affs_init_bitmap(sb, &tmp_flags); 525 if (ret) 526 return ret; 527 sb->s_flags = tmp_flags; 528 529 /* set up enough so that it can read an inode */ 530 531 root_inode = affs_iget(sb, root_block); 532 if (IS_ERR(root_inode)) 533 return PTR_ERR(root_inode); 534 535 if (affs_test_opt(AFFS_SB(sb)->s_flags, SF_INTL)) 536 sb->s_d_op = &affs_intl_dentry_operations; 537 else 538 sb->s_d_op = &affs_dentry_operations; 539 540 sb->s_root = d_make_root(root_inode); 541 if (!sb->s_root) { 542 pr_err("AFFS: Get root inode failed\n"); 543 return -ENOMEM; 544 } 545 546 sb->s_export_op = &affs_export_ops; 547 pr_debug("s_flags=%lX\n", sb->s_flags); 548 return 0; 549} 550 551static int 552affs_remount(struct super_block *sb, int *flags, char *data) 553{ 554 struct affs_sb_info *sbi = AFFS_SB(sb); 555 int blocksize; 556 kuid_t uid; 557 kgid_t gid; 558 int mode; 559 int reserved; 560 int root_block; 561 unsigned long mount_flags; 562 int res = 0; 563 char volume[32]; 564 char *prefix = NULL; 565 566 pr_debug("%s(flags=0x%x,opts=\"%s\")\n", __func__, *flags, data); 567 568 sync_filesystem(sb); 569 *flags |= SB_NODIRATIME; 570 571 memcpy(volume, sbi->s_volume, 32); 572 if (!parse_options(data, &uid, &gid, &mode, &reserved, &root_block, 573 &blocksize, &prefix, volume, 574 &mount_flags)) { 575 kfree(prefix); 576 return -EINVAL; 577 } 578 579 flush_delayed_work(&sbi->sb_work); 580 581 sbi->s_flags = mount_flags; 582 sbi->s_mode = mode; 583 sbi->s_uid = uid; 584 sbi->s_gid = gid; 585 /* protect against readers */ 586 spin_lock(&sbi->symlink_lock); 587 if (prefix) { 588 kfree(sbi->s_prefix); 589 sbi->s_prefix = prefix; 590 } 591 memcpy(sbi->s_volume, volume, 32); 592 spin_unlock(&sbi->symlink_lock); 593 594 if ((bool)(*flags & SB_RDONLY) == sb_rdonly(sb)) 595 return 0; 596 597 if (*flags & SB_RDONLY) 598 affs_free_bitmap(sb); 599 else 600 res = affs_init_bitmap(sb, flags); 601 602 return res; 603} 604 605static int 606affs_statfs(struct dentry *dentry, struct kstatfs *buf) 607{ 608 struct super_block *sb = dentry->d_sb; 609 int free; 610 u64 id = huge_encode_dev(sb->s_bdev->bd_dev); 611 612 pr_debug("%s() partsize=%d, reserved=%d\n", 613 __func__, AFFS_SB(sb)->s_partition_size, 614 AFFS_SB(sb)->s_reserved); 615 616 free = affs_count_free_blocks(sb); 617 buf->f_type = AFFS_SUPER_MAGIC; 618 buf->f_bsize = sb->s_blocksize; 619 buf->f_blocks = AFFS_SB(sb)->s_partition_size - AFFS_SB(sb)->s_reserved; 620 buf->f_bfree = free; 621 buf->f_bavail = free; 622 buf->f_fsid = u64_to_fsid(id); 623 buf->f_namelen = AFFSNAMEMAX; 624 return 0; 625} 626 627static struct dentry *affs_mount(struct file_system_type *fs_type, 628 int flags, const char *dev_name, void *data) 629{ 630 return mount_bdev(fs_type, flags, dev_name, data, affs_fill_super); 631} 632 633static void affs_kill_sb(struct super_block *sb) 634{ 635 struct affs_sb_info *sbi = AFFS_SB(sb); 636 kill_block_super(sb); 637 if (sbi) { 638 affs_free_bitmap(sb); 639 affs_brelse(sbi->s_root_bh); 640 kfree(sbi->s_prefix); 641 mutex_destroy(&sbi->s_bmlock); 642 kfree_rcu(sbi, rcu); 643 } 644} 645 646static struct file_system_type affs_fs_type = { 647 .owner = THIS_MODULE, 648 .name = "affs", 649 .mount = affs_mount, 650 .kill_sb = affs_kill_sb, 651 .fs_flags = FS_REQUIRES_DEV, 652}; 653MODULE_ALIAS_FS("affs"); 654 655static int __init init_affs_fs(void) 656{ 657 int err = init_inodecache(); 658 if (err) 659 goto out1; 660 err = register_filesystem(&affs_fs_type); 661 if (err) 662 goto out; 663 return 0; 664out: 665 destroy_inodecache(); 666out1: 667 return err; 668} 669 670static void __exit exit_affs_fs(void) 671{ 672 unregister_filesystem(&affs_fs_type); 673 destroy_inodecache(); 674} 675 676MODULE_DESCRIPTION("Amiga filesystem support for Linux"); 677MODULE_LICENSE("GPL"); 678 679module_init(init_affs_fs) 680module_exit(exit_affs_fs) 681