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