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/slab.h> 20 #include "affs.h" 21 22 extern struct timezone sys_tz; 23 24 static int affs_statfs(struct dentry *dentry, struct kstatfs *buf); 25 static int affs_remount (struct super_block *sb, int *flags, char *data); 26 27 static void 28 affs_commit_super(struct super_block *sb, int wait, int clean) 29 { 30 struct affs_sb_info *sbi = AFFS_SB(sb); 31 struct buffer_head *bh = sbi->s_root_bh; 32 struct affs_root_tail *tail = AFFS_ROOT_TAIL(sb, bh); 33 34 tail->bm_flag = cpu_to_be32(clean); 35 secs_to_datestamp(get_seconds(), &tail->disk_change); 36 affs_fix_checksum(sb, bh); 37 mark_buffer_dirty(bh); 38 if (wait) 39 sync_dirty_buffer(bh); 40 } 41 42 static void 43 affs_put_super(struct super_block *sb) 44 { 45 struct affs_sb_info *sbi = AFFS_SB(sb); 46 pr_debug("AFFS: put_super()\n"); 47 48 if (!(sb->s_flags & MS_RDONLY) && sb->s_dirt) 49 affs_commit_super(sb, 1, 1); 50 51 kfree(sbi->s_prefix); 52 affs_free_bitmap(sb); 53 affs_brelse(sbi->s_root_bh); 54 kfree(sbi); 55 sb->s_fs_info = NULL; 56 } 57 58 static void 59 affs_write_super(struct super_block *sb) 60 { 61 lock_super(sb); 62 if (!(sb->s_flags & MS_RDONLY)) 63 affs_commit_super(sb, 1, 2); 64 sb->s_dirt = 0; 65 unlock_super(sb); 66 67 pr_debug("AFFS: write_super() at %lu, clean=2\n", get_seconds()); 68 } 69 70 static int 71 affs_sync_fs(struct super_block *sb, int wait) 72 { 73 lock_super(sb); 74 affs_commit_super(sb, wait, 2); 75 sb->s_dirt = 0; 76 unlock_super(sb); 77 return 0; 78 } 79 80 static struct kmem_cache * affs_inode_cachep; 81 82 static struct inode *affs_alloc_inode(struct super_block *sb) 83 { 84 struct affs_inode_info *i; 85 86 i = kmem_cache_alloc(affs_inode_cachep, GFP_KERNEL); 87 if (!i) 88 return NULL; 89 90 i->vfs_inode.i_version = 1; 91 i->i_lc = NULL; 92 i->i_ext_bh = NULL; 93 i->i_pa_cnt = 0; 94 95 return &i->vfs_inode; 96 } 97 98 static void affs_i_callback(struct rcu_head *head) 99 { 100 struct inode *inode = container_of(head, struct inode, i_rcu); 101 INIT_LIST_HEAD(&inode->i_dentry); 102 kmem_cache_free(affs_inode_cachep, AFFS_I(inode)); 103 } 104 105 static void affs_destroy_inode(struct inode *inode) 106 { 107 call_rcu(&inode->i_rcu, affs_i_callback); 108 } 109 110 static void init_once(void *foo) 111 { 112 struct affs_inode_info *ei = (struct affs_inode_info *) foo; 113 114 sema_init(&ei->i_link_lock, 1); 115 sema_init(&ei->i_ext_lock, 1); 116 inode_init_once(&ei->vfs_inode); 117 } 118 119 static int init_inodecache(void) 120 { 121 affs_inode_cachep = kmem_cache_create("affs_inode_cache", 122 sizeof(struct affs_inode_info), 123 0, (SLAB_RECLAIM_ACCOUNT| 124 SLAB_MEM_SPREAD), 125 init_once); 126 if (affs_inode_cachep == NULL) 127 return -ENOMEM; 128 return 0; 129 } 130 131 static void destroy_inodecache(void) 132 { 133 kmem_cache_destroy(affs_inode_cachep); 134 } 135 136 static const struct super_operations affs_sops = { 137 .alloc_inode = affs_alloc_inode, 138 .destroy_inode = affs_destroy_inode, 139 .write_inode = affs_write_inode, 140 .evict_inode = affs_evict_inode, 141 .put_super = affs_put_super, 142 .write_super = affs_write_super, 143 .sync_fs = affs_sync_fs, 144 .statfs = affs_statfs, 145 .remount_fs = affs_remount, 146 .show_options = generic_show_options, 147 }; 148 149 enum { 150 Opt_bs, Opt_mode, Opt_mufs, Opt_prefix, Opt_protect, 151 Opt_reserved, Opt_root, Opt_setgid, Opt_setuid, 152 Opt_verbose, Opt_volume, Opt_ignore, Opt_err, 153 }; 154 155 static const match_table_t tokens = { 156 {Opt_bs, "bs=%u"}, 157 {Opt_mode, "mode=%o"}, 158 {Opt_mufs, "mufs"}, 159 {Opt_prefix, "prefix=%s"}, 160 {Opt_protect, "protect"}, 161 {Opt_reserved, "reserved=%u"}, 162 {Opt_root, "root=%u"}, 163 {Opt_setgid, "setgid=%u"}, 164 {Opt_setuid, "setuid=%u"}, 165 {Opt_verbose, "verbose"}, 166 {Opt_volume, "volume=%s"}, 167 {Opt_ignore, "grpquota"}, 168 {Opt_ignore, "noquota"}, 169 {Opt_ignore, "quota"}, 170 {Opt_ignore, "usrquota"}, 171 {Opt_err, NULL}, 172 }; 173 174 static int 175 parse_options(char *options, uid_t *uid, gid_t *gid, int *mode, int *reserved, s32 *root, 176 int *blocksize, char **prefix, char *volume, unsigned long *mount_opts) 177 { 178 char *p; 179 substring_t args[MAX_OPT_ARGS]; 180 181 /* Fill in defaults */ 182 183 *uid = current_uid(); 184 *gid = current_gid(); 185 *reserved = 2; 186 *root = -1; 187 *blocksize = -1; 188 volume[0] = ':'; 189 volume[1] = 0; 190 *mount_opts = 0; 191 if (!options) 192 return 1; 193 194 while ((p = strsep(&options, ",")) != NULL) { 195 int token, n, option; 196 if (!*p) 197 continue; 198 199 token = match_token(p, tokens, args); 200 switch (token) { 201 case Opt_bs: 202 if (match_int(&args[0], &n)) 203 return 0; 204 if (n != 512 && n != 1024 && n != 2048 205 && n != 4096) { 206 printk ("AFFS: Invalid blocksize (512, 1024, 2048, 4096 allowed)\n"); 207 return 0; 208 } 209 *blocksize = n; 210 break; 211 case Opt_mode: 212 if (match_octal(&args[0], &option)) 213 return 0; 214 *mode = option & 0777; 215 *mount_opts |= SF_SETMODE; 216 break; 217 case Opt_mufs: 218 *mount_opts |= SF_MUFS; 219 break; 220 case Opt_prefix: 221 *prefix = match_strdup(&args[0]); 222 if (!*prefix) 223 return 0; 224 *mount_opts |= SF_PREFIX; 225 break; 226 case Opt_protect: 227 *mount_opts |= SF_IMMUTABLE; 228 break; 229 case Opt_reserved: 230 if (match_int(&args[0], reserved)) 231 return 0; 232 break; 233 case Opt_root: 234 if (match_int(&args[0], root)) 235 return 0; 236 break; 237 case Opt_setgid: 238 if (match_int(&args[0], &option)) 239 return 0; 240 *gid = option; 241 *mount_opts |= SF_SETGID; 242 break; 243 case Opt_setuid: 244 if (match_int(&args[0], &option)) 245 return 0; 246 *uid = option; 247 *mount_opts |= SF_SETUID; 248 break; 249 case Opt_verbose: 250 *mount_opts |= SF_VERBOSE; 251 break; 252 case Opt_volume: { 253 char *vol = match_strdup(&args[0]); 254 if (!vol) 255 return 0; 256 strlcpy(volume, vol, 32); 257 kfree(vol); 258 break; 259 } 260 case Opt_ignore: 261 /* Silently ignore the quota options */ 262 break; 263 default: 264 printk("AFFS: Unrecognized mount option \"%s\" " 265 "or missing value\n", p); 266 return 0; 267 } 268 } 269 return 1; 270 } 271 272 /* This function definitely needs to be split up. Some fine day I'll 273 * hopefully have the guts to do so. Until then: sorry for the mess. 274 */ 275 276 static int affs_fill_super(struct super_block *sb, void *data, int silent) 277 { 278 struct affs_sb_info *sbi; 279 struct buffer_head *root_bh = NULL; 280 struct buffer_head *boot_bh; 281 struct inode *root_inode = NULL; 282 s32 root_block; 283 int size, blocksize; 284 u32 chksum; 285 int num_bm; 286 int i, j; 287 s32 key; 288 uid_t uid; 289 gid_t gid; 290 int reserved; 291 unsigned long mount_flags; 292 int tmp_flags; /* fix remount prototype... */ 293 u8 sig[4]; 294 int ret = -EINVAL; 295 296 save_mount_options(sb, data); 297 298 pr_debug("AFFS: read_super(%s)\n",data ? (const char *)data : "no options"); 299 300 sb->s_magic = AFFS_SUPER_MAGIC; 301 sb->s_op = &affs_sops; 302 sb->s_flags |= MS_NODIRATIME; 303 304 sbi = kzalloc(sizeof(struct affs_sb_info), GFP_KERNEL); 305 if (!sbi) 306 return -ENOMEM; 307 308 sb->s_fs_info = sbi; 309 mutex_init(&sbi->s_bmlock); 310 spin_lock_init(&sbi->symlink_lock); 311 312 if (!parse_options(data,&uid,&gid,&i,&reserved,&root_block, 313 &blocksize,&sbi->s_prefix, 314 sbi->s_volume, &mount_flags)) { 315 printk(KERN_ERR "AFFS: Error parsing options\n"); 316 kfree(sbi->s_prefix); 317 kfree(sbi); 318 return -EINVAL; 319 } 320 /* N.B. after this point s_prefix must be released */ 321 322 sbi->s_flags = mount_flags; 323 sbi->s_mode = i; 324 sbi->s_uid = uid; 325 sbi->s_gid = gid; 326 sbi->s_reserved= reserved; 327 328 /* Get the size of the device in 512-byte blocks. 329 * If we later see that the partition uses bigger 330 * blocks, we will have to change it. 331 */ 332 333 size = sb->s_bdev->bd_inode->i_size >> 9; 334 pr_debug("AFFS: initial blocksize=%d, #blocks=%d\n", 512, size); 335 336 affs_set_blocksize(sb, PAGE_SIZE); 337 /* Try to find root block. Its location depends on the block size. */ 338 339 i = 512; 340 j = 4096; 341 if (blocksize > 0) { 342 i = j = blocksize; 343 size = size / (blocksize / 512); 344 } 345 for (blocksize = i, key = 0; blocksize <= j; blocksize <<= 1, size >>= 1) { 346 sbi->s_root_block = root_block; 347 if (root_block < 0) 348 sbi->s_root_block = (reserved + size - 1) / 2; 349 pr_debug("AFFS: setting blocksize to %d\n", blocksize); 350 affs_set_blocksize(sb, blocksize); 351 sbi->s_partition_size = size; 352 353 /* The root block location that was calculated above is not 354 * correct if the partition size is an odd number of 512- 355 * byte blocks, which will be rounded down to a number of 356 * 1024-byte blocks, and if there were an even number of 357 * reserved blocks. Ideally, all partition checkers should 358 * report the real number of blocks of the real blocksize, 359 * but since this just cannot be done, we have to try to 360 * find the root block anyways. In the above case, it is one 361 * block behind the calculated one. So we check this one, too. 362 */ 363 for (num_bm = 0; num_bm < 2; num_bm++) { 364 pr_debug("AFFS: Dev %s, trying root=%u, bs=%d, " 365 "size=%d, reserved=%d\n", 366 sb->s_id, 367 sbi->s_root_block + num_bm, 368 blocksize, size, reserved); 369 root_bh = affs_bread(sb, sbi->s_root_block + num_bm); 370 if (!root_bh) 371 continue; 372 if (!affs_checksum_block(sb, root_bh) && 373 be32_to_cpu(AFFS_ROOT_HEAD(root_bh)->ptype) == T_SHORT && 374 be32_to_cpu(AFFS_ROOT_TAIL(sb, root_bh)->stype) == ST_ROOT) { 375 sbi->s_hashsize = blocksize / 4 - 56; 376 sbi->s_root_block += num_bm; 377 key = 1; 378 goto got_root; 379 } 380 affs_brelse(root_bh); 381 root_bh = NULL; 382 } 383 } 384 if (!silent) 385 printk(KERN_ERR "AFFS: No valid root block on device %s\n", 386 sb->s_id); 387 goto out_error; 388 389 /* N.B. after this point bh must be released */ 390 got_root: 391 root_block = sbi->s_root_block; 392 393 /* Find out which kind of FS we have */ 394 boot_bh = sb_bread(sb, 0); 395 if (!boot_bh) { 396 printk(KERN_ERR "AFFS: Cannot read boot block\n"); 397 goto out_error; 398 } 399 memcpy(sig, boot_bh->b_data, 4); 400 brelse(boot_bh); 401 chksum = be32_to_cpu(*(__be32 *)sig); 402 403 /* Dircache filesystems are compatible with non-dircache ones 404 * when reading. As long as they aren't supported, writing is 405 * not recommended. 406 */ 407 if ((chksum == FS_DCFFS || chksum == MUFS_DCFFS || chksum == FS_DCOFS 408 || chksum == MUFS_DCOFS) && !(sb->s_flags & MS_RDONLY)) { 409 printk(KERN_NOTICE "AFFS: Dircache FS - mounting %s read only\n", 410 sb->s_id); 411 sb->s_flags |= MS_RDONLY; 412 } 413 switch (chksum) { 414 case MUFS_FS: 415 case MUFS_INTLFFS: 416 case MUFS_DCFFS: 417 sbi->s_flags |= SF_MUFS; 418 /* fall thru */ 419 case FS_INTLFFS: 420 case FS_DCFFS: 421 sbi->s_flags |= SF_INTL; 422 break; 423 case MUFS_FFS: 424 sbi->s_flags |= SF_MUFS; 425 break; 426 case FS_FFS: 427 break; 428 case MUFS_OFS: 429 sbi->s_flags |= SF_MUFS; 430 /* fall thru */ 431 case FS_OFS: 432 sbi->s_flags |= SF_OFS; 433 sb->s_flags |= MS_NOEXEC; 434 break; 435 case MUFS_DCOFS: 436 case MUFS_INTLOFS: 437 sbi->s_flags |= SF_MUFS; 438 case FS_DCOFS: 439 case FS_INTLOFS: 440 sbi->s_flags |= SF_INTL | SF_OFS; 441 sb->s_flags |= MS_NOEXEC; 442 break; 443 default: 444 printk(KERN_ERR "AFFS: Unknown filesystem on device %s: %08X\n", 445 sb->s_id, chksum); 446 goto out_error; 447 } 448 449 if (mount_flags & SF_VERBOSE) { 450 u8 len = AFFS_ROOT_TAIL(sb, root_bh)->disk_name[0]; 451 printk(KERN_NOTICE "AFFS: Mounting volume \"%.*s\": Type=%.3s\\%c, Blocksize=%d\n", 452 len > 31 ? 31 : len, 453 AFFS_ROOT_TAIL(sb, root_bh)->disk_name + 1, 454 sig, sig[3] + '0', blocksize); 455 } 456 457 sb->s_flags |= MS_NODEV | MS_NOSUID; 458 459 sbi->s_data_blksize = sb->s_blocksize; 460 if (sbi->s_flags & SF_OFS) 461 sbi->s_data_blksize -= 24; 462 463 /* Keep super block in cache */ 464 sbi->s_root_bh = root_bh; 465 /* N.B. after this point s_root_bh must be released */ 466 467 tmp_flags = sb->s_flags; 468 if (affs_init_bitmap(sb, &tmp_flags)) 469 goto out_error; 470 sb->s_flags = tmp_flags; 471 472 /* set up enough so that it can read an inode */ 473 474 root_inode = affs_iget(sb, root_block); 475 if (IS_ERR(root_inode)) { 476 ret = PTR_ERR(root_inode); 477 goto out_error_noinode; 478 } 479 480 if (AFFS_SB(sb)->s_flags & SF_INTL) 481 sb->s_d_op = &affs_intl_dentry_operations; 482 else 483 sb->s_d_op = &affs_dentry_operations; 484 485 sb->s_root = d_alloc_root(root_inode); 486 if (!sb->s_root) { 487 printk(KERN_ERR "AFFS: Get root inode failed\n"); 488 goto out_error; 489 } 490 491 pr_debug("AFFS: s_flags=%lX\n",sb->s_flags); 492 return 0; 493 494 /* 495 * Begin the cascaded cleanup ... 496 */ 497 out_error: 498 if (root_inode) 499 iput(root_inode); 500 out_error_noinode: 501 kfree(sbi->s_bitmap); 502 affs_brelse(root_bh); 503 kfree(sbi->s_prefix); 504 kfree(sbi); 505 sb->s_fs_info = NULL; 506 return ret; 507 } 508 509 static int 510 affs_remount(struct super_block *sb, int *flags, char *data) 511 { 512 struct affs_sb_info *sbi = AFFS_SB(sb); 513 int blocksize; 514 uid_t uid; 515 gid_t gid; 516 int mode; 517 int reserved; 518 int root_block; 519 unsigned long mount_flags; 520 int res = 0; 521 char *new_opts = kstrdup(data, GFP_KERNEL); 522 char volume[32]; 523 char *prefix = NULL; 524 525 pr_debug("AFFS: remount(flags=0x%x,opts=\"%s\")\n",*flags,data); 526 527 *flags |= MS_NODIRATIME; 528 529 memcpy(volume, sbi->s_volume, 32); 530 if (!parse_options(data, &uid, &gid, &mode, &reserved, &root_block, 531 &blocksize, &prefix, volume, 532 &mount_flags)) { 533 kfree(prefix); 534 kfree(new_opts); 535 return -EINVAL; 536 } 537 538 replace_mount_options(sb, new_opts); 539 540 sbi->s_flags = mount_flags; 541 sbi->s_mode = mode; 542 sbi->s_uid = uid; 543 sbi->s_gid = gid; 544 /* protect against readers */ 545 spin_lock(&sbi->symlink_lock); 546 if (prefix) { 547 kfree(sbi->s_prefix); 548 sbi->s_prefix = prefix; 549 } 550 memcpy(sbi->s_volume, volume, 32); 551 spin_unlock(&sbi->symlink_lock); 552 553 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) 554 return 0; 555 556 if (*flags & MS_RDONLY) { 557 affs_write_super(sb); 558 affs_free_bitmap(sb); 559 } else 560 res = affs_init_bitmap(sb, flags); 561 562 return res; 563 } 564 565 static int 566 affs_statfs(struct dentry *dentry, struct kstatfs *buf) 567 { 568 struct super_block *sb = dentry->d_sb; 569 int free; 570 u64 id = huge_encode_dev(sb->s_bdev->bd_dev); 571 572 pr_debug("AFFS: statfs() partsize=%d, reserved=%d\n",AFFS_SB(sb)->s_partition_size, 573 AFFS_SB(sb)->s_reserved); 574 575 free = affs_count_free_blocks(sb); 576 buf->f_type = AFFS_SUPER_MAGIC; 577 buf->f_bsize = sb->s_blocksize; 578 buf->f_blocks = AFFS_SB(sb)->s_partition_size - AFFS_SB(sb)->s_reserved; 579 buf->f_bfree = free; 580 buf->f_bavail = free; 581 buf->f_fsid.val[0] = (u32)id; 582 buf->f_fsid.val[1] = (u32)(id >> 32); 583 buf->f_namelen = 30; 584 return 0; 585 } 586 587 static struct dentry *affs_mount(struct file_system_type *fs_type, 588 int flags, const char *dev_name, void *data) 589 { 590 return mount_bdev(fs_type, flags, dev_name, data, affs_fill_super); 591 } 592 593 static struct file_system_type affs_fs_type = { 594 .owner = THIS_MODULE, 595 .name = "affs", 596 .mount = affs_mount, 597 .kill_sb = kill_block_super, 598 .fs_flags = FS_REQUIRES_DEV, 599 }; 600 601 static int __init init_affs_fs(void) 602 { 603 int err = init_inodecache(); 604 if (err) 605 goto out1; 606 err = register_filesystem(&affs_fs_type); 607 if (err) 608 goto out; 609 return 0; 610 out: 611 destroy_inodecache(); 612 out1: 613 return err; 614 } 615 616 static void __exit exit_affs_fs(void) 617 { 618 unregister_filesystem(&affs_fs_type); 619 destroy_inodecache(); 620 } 621 622 MODULE_DESCRIPTION("Amiga filesystem support for Linux"); 623 MODULE_LICENSE("GPL"); 624 625 module_init(init_affs_fs) 626 module_exit(exit_affs_fs) 627