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