1 /* 2 * linux/fs/adfs/super.c 3 * 4 * Copyright (C) 1997-1999 Russell King 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License version 2 as 8 * published by the Free Software Foundation. 9 */ 10 #include <linux/module.h> 11 #include <linux/init.h> 12 #include <linux/buffer_head.h> 13 #include <linux/parser.h> 14 #include <linux/mount.h> 15 #include <linux/seq_file.h> 16 #include <linux/slab.h> 17 #include <linux/statfs.h> 18 #include <linux/user_namespace.h> 19 #include "adfs.h" 20 #include "dir_f.h" 21 #include "dir_fplus.h" 22 23 #define ADFS_DEFAULT_OWNER_MASK S_IRWXU 24 #define ADFS_DEFAULT_OTHER_MASK (S_IRWXG | S_IRWXO) 25 26 void __adfs_error(struct super_block *sb, const char *function, const char *fmt, ...) 27 { 28 char error_buf[128]; 29 va_list args; 30 31 va_start(args, fmt); 32 vsnprintf(error_buf, sizeof(error_buf), fmt, args); 33 va_end(args); 34 35 printk(KERN_CRIT "ADFS-fs error (device %s)%s%s: %s\n", 36 sb->s_id, function ? ": " : "", 37 function ? function : "", error_buf); 38 } 39 40 static int adfs_checkdiscrecord(struct adfs_discrecord *dr) 41 { 42 int i; 43 44 /* sector size must be 256, 512 or 1024 bytes */ 45 if (dr->log2secsize != 8 && 46 dr->log2secsize != 9 && 47 dr->log2secsize != 10) 48 return 1; 49 50 /* idlen must be at least log2secsize + 3 */ 51 if (dr->idlen < dr->log2secsize + 3) 52 return 1; 53 54 /* we cannot have such a large disc that we 55 * are unable to represent sector offsets in 56 * 32 bits. This works out at 2.0 TB. 57 */ 58 if (le32_to_cpu(dr->disc_size_high) >> dr->log2secsize) 59 return 1; 60 61 /* idlen must be no greater than 19 v2 [1.0] */ 62 if (dr->idlen > 19) 63 return 1; 64 65 /* reserved bytes should be zero */ 66 for (i = 0; i < sizeof(dr->unused52); i++) 67 if (dr->unused52[i] != 0) 68 return 1; 69 70 return 0; 71 } 72 73 static unsigned char adfs_calczonecheck(struct super_block *sb, unsigned char *map) 74 { 75 unsigned int v0, v1, v2, v3; 76 int i; 77 78 v0 = v1 = v2 = v3 = 0; 79 for (i = sb->s_blocksize - 4; i; i -= 4) { 80 v0 += map[i] + (v3 >> 8); 81 v3 &= 0xff; 82 v1 += map[i + 1] + (v0 >> 8); 83 v0 &= 0xff; 84 v2 += map[i + 2] + (v1 >> 8); 85 v1 &= 0xff; 86 v3 += map[i + 3] + (v2 >> 8); 87 v2 &= 0xff; 88 } 89 v0 += v3 >> 8; 90 v1 += map[1] + (v0 >> 8); 91 v2 += map[2] + (v1 >> 8); 92 v3 += map[3] + (v2 >> 8); 93 94 return v0 ^ v1 ^ v2 ^ v3; 95 } 96 97 static int adfs_checkmap(struct super_block *sb, struct adfs_discmap *dm) 98 { 99 unsigned char crosscheck = 0, zonecheck = 1; 100 int i; 101 102 for (i = 0; i < ADFS_SB(sb)->s_map_size; i++) { 103 unsigned char *map; 104 105 map = dm[i].dm_bh->b_data; 106 107 if (adfs_calczonecheck(sb, map) != map[0]) { 108 adfs_error(sb, "zone %d fails zonecheck", i); 109 zonecheck = 0; 110 } 111 crosscheck ^= map[3]; 112 } 113 if (crosscheck != 0xff) 114 adfs_error(sb, "crosscheck != 0xff"); 115 return crosscheck == 0xff && zonecheck; 116 } 117 118 static void adfs_put_super(struct super_block *sb) 119 { 120 int i; 121 struct adfs_sb_info *asb = ADFS_SB(sb); 122 123 for (i = 0; i < asb->s_map_size; i++) 124 brelse(asb->s_map[i].dm_bh); 125 kfree(asb->s_map); 126 kfree_rcu(asb, rcu); 127 } 128 129 static int adfs_show_options(struct seq_file *seq, struct dentry *root) 130 { 131 struct adfs_sb_info *asb = ADFS_SB(root->d_sb); 132 133 if (!uid_eq(asb->s_uid, GLOBAL_ROOT_UID)) 134 seq_printf(seq, ",uid=%u", from_kuid_munged(&init_user_ns, asb->s_uid)); 135 if (!gid_eq(asb->s_gid, GLOBAL_ROOT_GID)) 136 seq_printf(seq, ",gid=%u", from_kgid_munged(&init_user_ns, asb->s_gid)); 137 if (asb->s_owner_mask != ADFS_DEFAULT_OWNER_MASK) 138 seq_printf(seq, ",ownmask=%o", asb->s_owner_mask); 139 if (asb->s_other_mask != ADFS_DEFAULT_OTHER_MASK) 140 seq_printf(seq, ",othmask=%o", asb->s_other_mask); 141 if (asb->s_ftsuffix != 0) 142 seq_printf(seq, ",ftsuffix=%u", asb->s_ftsuffix); 143 144 return 0; 145 } 146 147 enum {Opt_uid, Opt_gid, Opt_ownmask, Opt_othmask, Opt_ftsuffix, Opt_err}; 148 149 static const match_table_t tokens = { 150 {Opt_uid, "uid=%u"}, 151 {Opt_gid, "gid=%u"}, 152 {Opt_ownmask, "ownmask=%o"}, 153 {Opt_othmask, "othmask=%o"}, 154 {Opt_ftsuffix, "ftsuffix=%u"}, 155 {Opt_err, NULL} 156 }; 157 158 static int parse_options(struct super_block *sb, char *options) 159 { 160 char *p; 161 struct adfs_sb_info *asb = ADFS_SB(sb); 162 int option; 163 164 if (!options) 165 return 0; 166 167 while ((p = strsep(&options, ",")) != NULL) { 168 substring_t args[MAX_OPT_ARGS]; 169 int token; 170 if (!*p) 171 continue; 172 173 token = match_token(p, tokens, args); 174 switch (token) { 175 case Opt_uid: 176 if (match_int(args, &option)) 177 return -EINVAL; 178 asb->s_uid = make_kuid(current_user_ns(), option); 179 if (!uid_valid(asb->s_uid)) 180 return -EINVAL; 181 break; 182 case Opt_gid: 183 if (match_int(args, &option)) 184 return -EINVAL; 185 asb->s_gid = make_kgid(current_user_ns(), option); 186 if (!gid_valid(asb->s_gid)) 187 return -EINVAL; 188 break; 189 case Opt_ownmask: 190 if (match_octal(args, &option)) 191 return -EINVAL; 192 asb->s_owner_mask = option; 193 break; 194 case Opt_othmask: 195 if (match_octal(args, &option)) 196 return -EINVAL; 197 asb->s_other_mask = option; 198 break; 199 case Opt_ftsuffix: 200 if (match_int(args, &option)) 201 return -EINVAL; 202 asb->s_ftsuffix = option; 203 break; 204 default: 205 printk("ADFS-fs: unrecognised mount option \"%s\" " 206 "or missing value\n", p); 207 return -EINVAL; 208 } 209 } 210 return 0; 211 } 212 213 static int adfs_remount(struct super_block *sb, int *flags, char *data) 214 { 215 *flags |= MS_NODIRATIME; 216 return parse_options(sb, data); 217 } 218 219 static int adfs_statfs(struct dentry *dentry, struct kstatfs *buf) 220 { 221 struct super_block *sb = dentry->d_sb; 222 struct adfs_sb_info *sbi = ADFS_SB(sb); 223 u64 id = huge_encode_dev(sb->s_bdev->bd_dev); 224 225 buf->f_type = ADFS_SUPER_MAGIC; 226 buf->f_namelen = sbi->s_namelen; 227 buf->f_bsize = sb->s_blocksize; 228 buf->f_blocks = sbi->s_size; 229 buf->f_files = sbi->s_ids_per_zone * sbi->s_map_size; 230 buf->f_bavail = 231 buf->f_bfree = adfs_map_free(sb); 232 buf->f_ffree = (long)(buf->f_bfree * buf->f_files) / (long)buf->f_blocks; 233 buf->f_fsid.val[0] = (u32)id; 234 buf->f_fsid.val[1] = (u32)(id >> 32); 235 236 return 0; 237 } 238 239 static struct kmem_cache *adfs_inode_cachep; 240 241 static struct inode *adfs_alloc_inode(struct super_block *sb) 242 { 243 struct adfs_inode_info *ei; 244 ei = (struct adfs_inode_info *)kmem_cache_alloc(adfs_inode_cachep, GFP_KERNEL); 245 if (!ei) 246 return NULL; 247 return &ei->vfs_inode; 248 } 249 250 static void adfs_i_callback(struct rcu_head *head) 251 { 252 struct inode *inode = container_of(head, struct inode, i_rcu); 253 kmem_cache_free(adfs_inode_cachep, ADFS_I(inode)); 254 } 255 256 static void adfs_destroy_inode(struct inode *inode) 257 { 258 call_rcu(&inode->i_rcu, adfs_i_callback); 259 } 260 261 static void init_once(void *foo) 262 { 263 struct adfs_inode_info *ei = (struct adfs_inode_info *) foo; 264 265 inode_init_once(&ei->vfs_inode); 266 } 267 268 static int init_inodecache(void) 269 { 270 adfs_inode_cachep = kmem_cache_create("adfs_inode_cache", 271 sizeof(struct adfs_inode_info), 272 0, (SLAB_RECLAIM_ACCOUNT| 273 SLAB_MEM_SPREAD), 274 init_once); 275 if (adfs_inode_cachep == NULL) 276 return -ENOMEM; 277 return 0; 278 } 279 280 static void destroy_inodecache(void) 281 { 282 /* 283 * Make sure all delayed rcu free inodes are flushed before we 284 * destroy cache. 285 */ 286 rcu_barrier(); 287 kmem_cache_destroy(adfs_inode_cachep); 288 } 289 290 static const struct super_operations adfs_sops = { 291 .alloc_inode = adfs_alloc_inode, 292 .destroy_inode = adfs_destroy_inode, 293 .write_inode = adfs_write_inode, 294 .put_super = adfs_put_super, 295 .statfs = adfs_statfs, 296 .remount_fs = adfs_remount, 297 .show_options = adfs_show_options, 298 }; 299 300 static struct adfs_discmap *adfs_read_map(struct super_block *sb, struct adfs_discrecord *dr) 301 { 302 struct adfs_discmap *dm; 303 unsigned int map_addr, zone_size, nzones; 304 int i, zone; 305 struct adfs_sb_info *asb = ADFS_SB(sb); 306 307 nzones = asb->s_map_size; 308 zone_size = (8 << dr->log2secsize) - le16_to_cpu(dr->zone_spare); 309 map_addr = (nzones >> 1) * zone_size - 310 ((nzones > 1) ? ADFS_DR_SIZE_BITS : 0); 311 map_addr = signed_asl(map_addr, asb->s_map2blk); 312 313 asb->s_ids_per_zone = zone_size / (asb->s_idlen + 1); 314 315 dm = kmalloc(nzones * sizeof(*dm), GFP_KERNEL); 316 if (dm == NULL) { 317 adfs_error(sb, "not enough memory"); 318 return NULL; 319 } 320 321 for (zone = 0; zone < nzones; zone++, map_addr++) { 322 dm[zone].dm_startbit = 0; 323 dm[zone].dm_endbit = zone_size; 324 dm[zone].dm_startblk = zone * zone_size - ADFS_DR_SIZE_BITS; 325 dm[zone].dm_bh = sb_bread(sb, map_addr); 326 327 if (!dm[zone].dm_bh) { 328 adfs_error(sb, "unable to read map"); 329 goto error_free; 330 } 331 } 332 333 /* adjust the limits for the first and last map zones */ 334 i = zone - 1; 335 dm[0].dm_startblk = 0; 336 dm[0].dm_startbit = ADFS_DR_SIZE_BITS; 337 dm[i].dm_endbit = (le32_to_cpu(dr->disc_size_high) << (32 - dr->log2bpmb)) + 338 (le32_to_cpu(dr->disc_size) >> dr->log2bpmb) + 339 (ADFS_DR_SIZE_BITS - i * zone_size); 340 341 if (adfs_checkmap(sb, dm)) 342 return dm; 343 344 adfs_error(sb, "map corrupted"); 345 346 error_free: 347 while (--zone >= 0) 348 brelse(dm[zone].dm_bh); 349 350 kfree(dm); 351 return NULL; 352 } 353 354 static inline unsigned long adfs_discsize(struct adfs_discrecord *dr, int block_bits) 355 { 356 unsigned long discsize; 357 358 discsize = le32_to_cpu(dr->disc_size_high) << (32 - block_bits); 359 discsize |= le32_to_cpu(dr->disc_size) >> block_bits; 360 361 return discsize; 362 } 363 364 static int adfs_fill_super(struct super_block *sb, void *data, int silent) 365 { 366 struct adfs_discrecord *dr; 367 struct buffer_head *bh; 368 struct object_info root_obj; 369 unsigned char *b_data; 370 struct adfs_sb_info *asb; 371 struct inode *root; 372 373 sb->s_flags |= MS_NODIRATIME; 374 375 asb = kzalloc(sizeof(*asb), GFP_KERNEL); 376 if (!asb) 377 return -ENOMEM; 378 sb->s_fs_info = asb; 379 380 /* set default options */ 381 asb->s_uid = GLOBAL_ROOT_UID; 382 asb->s_gid = GLOBAL_ROOT_GID; 383 asb->s_owner_mask = ADFS_DEFAULT_OWNER_MASK; 384 asb->s_other_mask = ADFS_DEFAULT_OTHER_MASK; 385 asb->s_ftsuffix = 0; 386 387 if (parse_options(sb, data)) 388 goto error; 389 390 sb_set_blocksize(sb, BLOCK_SIZE); 391 if (!(bh = sb_bread(sb, ADFS_DISCRECORD / BLOCK_SIZE))) { 392 adfs_error(sb, "unable to read superblock"); 393 goto error; 394 } 395 396 b_data = bh->b_data + (ADFS_DISCRECORD % BLOCK_SIZE); 397 398 if (adfs_checkbblk(b_data)) { 399 if (!silent) 400 printk("VFS: Can't find an adfs filesystem on dev " 401 "%s.\n", sb->s_id); 402 goto error_free_bh; 403 } 404 405 dr = (struct adfs_discrecord *)(b_data + ADFS_DR_OFFSET); 406 407 /* 408 * Do some sanity checks on the ADFS disc record 409 */ 410 if (adfs_checkdiscrecord(dr)) { 411 if (!silent) 412 printk("VPS: Can't find an adfs filesystem on dev " 413 "%s.\n", sb->s_id); 414 goto error_free_bh; 415 } 416 417 brelse(bh); 418 if (sb_set_blocksize(sb, 1 << dr->log2secsize)) { 419 bh = sb_bread(sb, ADFS_DISCRECORD / sb->s_blocksize); 420 if (!bh) { 421 adfs_error(sb, "couldn't read superblock on " 422 "2nd try."); 423 goto error; 424 } 425 b_data = bh->b_data + (ADFS_DISCRECORD % sb->s_blocksize); 426 if (adfs_checkbblk(b_data)) { 427 adfs_error(sb, "disc record mismatch, very weird!"); 428 goto error_free_bh; 429 } 430 dr = (struct adfs_discrecord *)(b_data + ADFS_DR_OFFSET); 431 } else { 432 if (!silent) 433 printk(KERN_ERR "VFS: Unsupported blocksize on dev " 434 "%s.\n", sb->s_id); 435 goto error; 436 } 437 438 /* 439 * blocksize on this device should now be set to the ADFS log2secsize 440 */ 441 442 sb->s_magic = ADFS_SUPER_MAGIC; 443 asb->s_idlen = dr->idlen; 444 asb->s_map_size = dr->nzones | (dr->nzones_high << 8); 445 asb->s_map2blk = dr->log2bpmb - dr->log2secsize; 446 asb->s_size = adfs_discsize(dr, sb->s_blocksize_bits); 447 asb->s_version = dr->format_version; 448 asb->s_log2sharesize = dr->log2sharesize; 449 450 asb->s_map = adfs_read_map(sb, dr); 451 if (!asb->s_map) 452 goto error_free_bh; 453 454 brelse(bh); 455 456 /* 457 * set up enough so that we can read an inode 458 */ 459 sb->s_op = &adfs_sops; 460 461 dr = (struct adfs_discrecord *)(asb->s_map[0].dm_bh->b_data + 4); 462 463 root_obj.parent_id = root_obj.file_id = le32_to_cpu(dr->root); 464 root_obj.name_len = 0; 465 /* Set root object date as 01 Jan 1987 00:00:00 */ 466 root_obj.loadaddr = 0xfff0003f; 467 root_obj.execaddr = 0xec22c000; 468 root_obj.size = ADFS_NEWDIR_SIZE; 469 root_obj.attr = ADFS_NDA_DIRECTORY | ADFS_NDA_OWNER_READ | 470 ADFS_NDA_OWNER_WRITE | ADFS_NDA_PUBLIC_READ; 471 root_obj.filetype = -1; 472 473 /* 474 * If this is a F+ disk with variable length directories, 475 * get the root_size from the disc record. 476 */ 477 if (asb->s_version) { 478 root_obj.size = le32_to_cpu(dr->root_size); 479 asb->s_dir = &adfs_fplus_dir_ops; 480 asb->s_namelen = ADFS_FPLUS_NAME_LEN; 481 } else { 482 asb->s_dir = &adfs_f_dir_ops; 483 asb->s_namelen = ADFS_F_NAME_LEN; 484 } 485 /* 486 * ,xyz hex filetype suffix may be added by driver 487 * to files that have valid RISC OS filetype 488 */ 489 if (asb->s_ftsuffix) 490 asb->s_namelen += 4; 491 492 sb->s_d_op = &adfs_dentry_operations; 493 root = adfs_iget(sb, &root_obj); 494 sb->s_root = d_make_root(root); 495 if (!sb->s_root) { 496 int i; 497 for (i = 0; i < asb->s_map_size; i++) 498 brelse(asb->s_map[i].dm_bh); 499 kfree(asb->s_map); 500 adfs_error(sb, "get root inode failed\n"); 501 goto error; 502 } 503 return 0; 504 505 error_free_bh: 506 brelse(bh); 507 error: 508 sb->s_fs_info = NULL; 509 kfree(asb); 510 return -EINVAL; 511 } 512 513 static struct dentry *adfs_mount(struct file_system_type *fs_type, 514 int flags, const char *dev_name, void *data) 515 { 516 return mount_bdev(fs_type, flags, dev_name, data, adfs_fill_super); 517 } 518 519 static struct file_system_type adfs_fs_type = { 520 .owner = THIS_MODULE, 521 .name = "adfs", 522 .mount = adfs_mount, 523 .kill_sb = kill_block_super, 524 .fs_flags = FS_REQUIRES_DEV, 525 }; 526 MODULE_ALIAS_FS("adfs"); 527 528 static int __init init_adfs_fs(void) 529 { 530 int err = init_inodecache(); 531 if (err) 532 goto out1; 533 err = register_filesystem(&adfs_fs_type); 534 if (err) 535 goto out; 536 return 0; 537 out: 538 destroy_inodecache(); 539 out1: 540 return err; 541 } 542 543 static void __exit exit_adfs_fs(void) 544 { 545 unregister_filesystem(&adfs_fs_type); 546 destroy_inodecache(); 547 } 548 549 module_init(init_adfs_fs) 550 module_exit(exit_adfs_fs) 551 MODULE_LICENSE("GPL"); 552