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 kmem_cache_free(adfs_inode_cachep, ADFS_I(inode)); 250 } 251 252 static void adfs_destroy_inode(struct inode *inode) 253 { 254 call_rcu(&inode->i_rcu, adfs_i_callback); 255 } 256 257 static void init_once(void *foo) 258 { 259 struct adfs_inode_info *ei = (struct adfs_inode_info *) foo; 260 261 inode_init_once(&ei->vfs_inode); 262 } 263 264 static int init_inodecache(void) 265 { 266 adfs_inode_cachep = kmem_cache_create("adfs_inode_cache", 267 sizeof(struct adfs_inode_info), 268 0, (SLAB_RECLAIM_ACCOUNT| 269 SLAB_MEM_SPREAD), 270 init_once); 271 if (adfs_inode_cachep == NULL) 272 return -ENOMEM; 273 return 0; 274 } 275 276 static void destroy_inodecache(void) 277 { 278 kmem_cache_destroy(adfs_inode_cachep); 279 } 280 281 static const struct super_operations adfs_sops = { 282 .alloc_inode = adfs_alloc_inode, 283 .destroy_inode = adfs_destroy_inode, 284 .write_inode = adfs_write_inode, 285 .put_super = adfs_put_super, 286 .statfs = adfs_statfs, 287 .remount_fs = adfs_remount, 288 .show_options = adfs_show_options, 289 }; 290 291 static struct adfs_discmap *adfs_read_map(struct super_block *sb, struct adfs_discrecord *dr) 292 { 293 struct adfs_discmap *dm; 294 unsigned int map_addr, zone_size, nzones; 295 int i, zone; 296 struct adfs_sb_info *asb = ADFS_SB(sb); 297 298 nzones = asb->s_map_size; 299 zone_size = (8 << dr->log2secsize) - le16_to_cpu(dr->zone_spare); 300 map_addr = (nzones >> 1) * zone_size - 301 ((nzones > 1) ? ADFS_DR_SIZE_BITS : 0); 302 map_addr = signed_asl(map_addr, asb->s_map2blk); 303 304 asb->s_ids_per_zone = zone_size / (asb->s_idlen + 1); 305 306 dm = kmalloc(nzones * sizeof(*dm), GFP_KERNEL); 307 if (dm == NULL) { 308 adfs_error(sb, "not enough memory"); 309 return NULL; 310 } 311 312 for (zone = 0; zone < nzones; zone++, map_addr++) { 313 dm[zone].dm_startbit = 0; 314 dm[zone].dm_endbit = zone_size; 315 dm[zone].dm_startblk = zone * zone_size - ADFS_DR_SIZE_BITS; 316 dm[zone].dm_bh = sb_bread(sb, map_addr); 317 318 if (!dm[zone].dm_bh) { 319 adfs_error(sb, "unable to read map"); 320 goto error_free; 321 } 322 } 323 324 /* adjust the limits for the first and last map zones */ 325 i = zone - 1; 326 dm[0].dm_startblk = 0; 327 dm[0].dm_startbit = ADFS_DR_SIZE_BITS; 328 dm[i].dm_endbit = (le32_to_cpu(dr->disc_size_high) << (32 - dr->log2bpmb)) + 329 (le32_to_cpu(dr->disc_size) >> dr->log2bpmb) + 330 (ADFS_DR_SIZE_BITS - i * zone_size); 331 332 if (adfs_checkmap(sb, dm)) 333 return dm; 334 335 adfs_error(sb, "map corrupted"); 336 337 error_free: 338 while (--zone >= 0) 339 brelse(dm[zone].dm_bh); 340 341 kfree(dm); 342 return NULL; 343 } 344 345 static inline unsigned long adfs_discsize(struct adfs_discrecord *dr, int block_bits) 346 { 347 unsigned long discsize; 348 349 discsize = le32_to_cpu(dr->disc_size_high) << (32 - block_bits); 350 discsize |= le32_to_cpu(dr->disc_size) >> block_bits; 351 352 return discsize; 353 } 354 355 static int adfs_fill_super(struct super_block *sb, void *data, int silent) 356 { 357 struct adfs_discrecord *dr; 358 struct buffer_head *bh; 359 struct object_info root_obj; 360 unsigned char *b_data; 361 struct adfs_sb_info *asb; 362 struct inode *root; 363 364 sb->s_flags |= MS_NODIRATIME; 365 366 asb = kzalloc(sizeof(*asb), GFP_KERNEL); 367 if (!asb) 368 return -ENOMEM; 369 sb->s_fs_info = asb; 370 371 /* set default options */ 372 asb->s_uid = 0; 373 asb->s_gid = 0; 374 asb->s_owner_mask = ADFS_DEFAULT_OWNER_MASK; 375 asb->s_other_mask = ADFS_DEFAULT_OTHER_MASK; 376 asb->s_ftsuffix = 0; 377 378 if (parse_options(sb, data)) 379 goto error; 380 381 sb_set_blocksize(sb, BLOCK_SIZE); 382 if (!(bh = sb_bread(sb, ADFS_DISCRECORD / BLOCK_SIZE))) { 383 adfs_error(sb, "unable to read superblock"); 384 goto error; 385 } 386 387 b_data = bh->b_data + (ADFS_DISCRECORD % BLOCK_SIZE); 388 389 if (adfs_checkbblk(b_data)) { 390 if (!silent) 391 printk("VFS: Can't find an adfs filesystem on dev " 392 "%s.\n", sb->s_id); 393 goto error_free_bh; 394 } 395 396 dr = (struct adfs_discrecord *)(b_data + ADFS_DR_OFFSET); 397 398 /* 399 * Do some sanity checks on the ADFS disc record 400 */ 401 if (adfs_checkdiscrecord(dr)) { 402 if (!silent) 403 printk("VPS: Can't find an adfs filesystem on dev " 404 "%s.\n", sb->s_id); 405 goto error_free_bh; 406 } 407 408 brelse(bh); 409 if (sb_set_blocksize(sb, 1 << dr->log2secsize)) { 410 bh = sb_bread(sb, ADFS_DISCRECORD / sb->s_blocksize); 411 if (!bh) { 412 adfs_error(sb, "couldn't read superblock on " 413 "2nd try."); 414 goto error; 415 } 416 b_data = bh->b_data + (ADFS_DISCRECORD % sb->s_blocksize); 417 if (adfs_checkbblk(b_data)) { 418 adfs_error(sb, "disc record mismatch, very weird!"); 419 goto error_free_bh; 420 } 421 dr = (struct adfs_discrecord *)(b_data + ADFS_DR_OFFSET); 422 } else { 423 if (!silent) 424 printk(KERN_ERR "VFS: Unsupported blocksize on dev " 425 "%s.\n", sb->s_id); 426 goto error; 427 } 428 429 /* 430 * blocksize on this device should now be set to the ADFS log2secsize 431 */ 432 433 sb->s_magic = ADFS_SUPER_MAGIC; 434 asb->s_idlen = dr->idlen; 435 asb->s_map_size = dr->nzones | (dr->nzones_high << 8); 436 asb->s_map2blk = dr->log2bpmb - dr->log2secsize; 437 asb->s_size = adfs_discsize(dr, sb->s_blocksize_bits); 438 asb->s_version = dr->format_version; 439 asb->s_log2sharesize = dr->log2sharesize; 440 441 asb->s_map = adfs_read_map(sb, dr); 442 if (!asb->s_map) 443 goto error_free_bh; 444 445 brelse(bh); 446 447 /* 448 * set up enough so that we can read an inode 449 */ 450 sb->s_op = &adfs_sops; 451 452 dr = (struct adfs_discrecord *)(asb->s_map[0].dm_bh->b_data + 4); 453 454 root_obj.parent_id = root_obj.file_id = le32_to_cpu(dr->root); 455 root_obj.name_len = 0; 456 /* Set root object date as 01 Jan 1987 00:00:00 */ 457 root_obj.loadaddr = 0xfff0003f; 458 root_obj.execaddr = 0xec22c000; 459 root_obj.size = ADFS_NEWDIR_SIZE; 460 root_obj.attr = ADFS_NDA_DIRECTORY | ADFS_NDA_OWNER_READ | 461 ADFS_NDA_OWNER_WRITE | ADFS_NDA_PUBLIC_READ; 462 root_obj.filetype = -1; 463 464 /* 465 * If this is a F+ disk with variable length directories, 466 * get the root_size from the disc record. 467 */ 468 if (asb->s_version) { 469 root_obj.size = le32_to_cpu(dr->root_size); 470 asb->s_dir = &adfs_fplus_dir_ops; 471 asb->s_namelen = ADFS_FPLUS_NAME_LEN; 472 } else { 473 asb->s_dir = &adfs_f_dir_ops; 474 asb->s_namelen = ADFS_F_NAME_LEN; 475 } 476 /* 477 * ,xyz hex filetype suffix may be added by driver 478 * to files that have valid RISC OS filetype 479 */ 480 if (asb->s_ftsuffix) 481 asb->s_namelen += 4; 482 483 sb->s_d_op = &adfs_dentry_operations; 484 root = adfs_iget(sb, &root_obj); 485 sb->s_root = d_make_root(root); 486 if (!sb->s_root) { 487 int i; 488 for (i = 0; i < asb->s_map_size; i++) 489 brelse(asb->s_map[i].dm_bh); 490 kfree(asb->s_map); 491 adfs_error(sb, "get root inode failed\n"); 492 goto error; 493 } 494 return 0; 495 496 error_free_bh: 497 brelse(bh); 498 error: 499 sb->s_fs_info = NULL; 500 kfree(asb); 501 return -EINVAL; 502 } 503 504 static struct dentry *adfs_mount(struct file_system_type *fs_type, 505 int flags, const char *dev_name, void *data) 506 { 507 return mount_bdev(fs_type, flags, dev_name, data, adfs_fill_super); 508 } 509 510 static struct file_system_type adfs_fs_type = { 511 .owner = THIS_MODULE, 512 .name = "adfs", 513 .mount = adfs_mount, 514 .kill_sb = kill_block_super, 515 .fs_flags = FS_REQUIRES_DEV, 516 }; 517 518 static int __init init_adfs_fs(void) 519 { 520 int err = init_inodecache(); 521 if (err) 522 goto out1; 523 err = register_filesystem(&adfs_fs_type); 524 if (err) 525 goto out; 526 return 0; 527 out: 528 destroy_inodecache(); 529 out1: 530 return err; 531 } 532 533 static void __exit exit_adfs_fs(void) 534 { 535 unregister_filesystem(&adfs_fs_type); 536 destroy_inodecache(); 537 } 538 539 module_init(init_adfs_fs) 540 module_exit(exit_adfs_fs) 541 MODULE_LICENSE("GPL"); 542