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/smp_lock.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 lock_kernel(); 123 124 for (i = 0; i < asb->s_map_size; i++) 125 brelse(asb->s_map[i].dm_bh); 126 kfree(asb->s_map); 127 kfree(asb); 128 sb->s_fs_info = NULL; 129 130 unlock_kernel(); 131 } 132 133 static int adfs_show_options(struct seq_file *seq, struct vfsmount *mnt) 134 { 135 struct adfs_sb_info *asb = ADFS_SB(mnt->mnt_sb); 136 137 if (asb->s_uid != 0) 138 seq_printf(seq, ",uid=%u", asb->s_uid); 139 if (asb->s_gid != 0) 140 seq_printf(seq, ",gid=%u", asb->s_gid); 141 if (asb->s_owner_mask != ADFS_DEFAULT_OWNER_MASK) 142 seq_printf(seq, ",ownmask=%o", asb->s_owner_mask); 143 if (asb->s_other_mask != ADFS_DEFAULT_OTHER_MASK) 144 seq_printf(seq, ",othmask=%o", asb->s_other_mask); 145 146 return 0; 147 } 148 149 enum {Opt_uid, Opt_gid, Opt_ownmask, Opt_othmask, Opt_err}; 150 151 static const match_table_t tokens = { 152 {Opt_uid, "uid=%u"}, 153 {Opt_gid, "gid=%u"}, 154 {Opt_ownmask, "ownmask=%o"}, 155 {Opt_othmask, "othmask=%o"}, 156 {Opt_err, NULL} 157 }; 158 159 static int parse_options(struct super_block *sb, char *options) 160 { 161 char *p; 162 struct adfs_sb_info *asb = ADFS_SB(sb); 163 int option; 164 165 if (!options) 166 return 0; 167 168 while ((p = strsep(&options, ",")) != NULL) { 169 substring_t args[MAX_OPT_ARGS]; 170 int token; 171 if (!*p) 172 continue; 173 174 token = match_token(p, tokens, args); 175 switch (token) { 176 case Opt_uid: 177 if (match_int(args, &option)) 178 return -EINVAL; 179 asb->s_uid = option; 180 break; 181 case Opt_gid: 182 if (match_int(args, &option)) 183 return -EINVAL; 184 asb->s_gid = option; 185 break; 186 case Opt_ownmask: 187 if (match_octal(args, &option)) 188 return -EINVAL; 189 asb->s_owner_mask = option; 190 break; 191 case Opt_othmask: 192 if (match_octal(args, &option)) 193 return -EINVAL; 194 asb->s_other_mask = option; 195 break; 196 default: 197 printk("ADFS-fs: unrecognised mount option \"%s\" " 198 "or missing value\n", p); 199 return -EINVAL; 200 } 201 } 202 return 0; 203 } 204 205 static int adfs_remount(struct super_block *sb, int *flags, char *data) 206 { 207 *flags |= MS_NODIRATIME; 208 return parse_options(sb, data); 209 } 210 211 static int adfs_statfs(struct dentry *dentry, struct kstatfs *buf) 212 { 213 struct super_block *sb = dentry->d_sb; 214 struct adfs_sb_info *sbi = ADFS_SB(sb); 215 u64 id = huge_encode_dev(sb->s_bdev->bd_dev); 216 217 buf->f_type = ADFS_SUPER_MAGIC; 218 buf->f_namelen = sbi->s_namelen; 219 buf->f_bsize = sb->s_blocksize; 220 buf->f_blocks = sbi->s_size; 221 buf->f_files = sbi->s_ids_per_zone * sbi->s_map_size; 222 buf->f_bavail = 223 buf->f_bfree = adfs_map_free(sb); 224 buf->f_ffree = (long)(buf->f_bfree * buf->f_files) / (long)buf->f_blocks; 225 buf->f_fsid.val[0] = (u32)id; 226 buf->f_fsid.val[1] = (u32)(id >> 32); 227 228 return 0; 229 } 230 231 static struct kmem_cache *adfs_inode_cachep; 232 233 static struct inode *adfs_alloc_inode(struct super_block *sb) 234 { 235 struct adfs_inode_info *ei; 236 ei = (struct adfs_inode_info *)kmem_cache_alloc(adfs_inode_cachep, GFP_KERNEL); 237 if (!ei) 238 return NULL; 239 return &ei->vfs_inode; 240 } 241 242 static void adfs_destroy_inode(struct inode *inode) 243 { 244 kmem_cache_free(adfs_inode_cachep, ADFS_I(inode)); 245 } 246 247 static void init_once(void *foo) 248 { 249 struct adfs_inode_info *ei = (struct adfs_inode_info *) foo; 250 251 inode_init_once(&ei->vfs_inode); 252 } 253 254 static int init_inodecache(void) 255 { 256 adfs_inode_cachep = kmem_cache_create("adfs_inode_cache", 257 sizeof(struct adfs_inode_info), 258 0, (SLAB_RECLAIM_ACCOUNT| 259 SLAB_MEM_SPREAD), 260 init_once); 261 if (adfs_inode_cachep == NULL) 262 return -ENOMEM; 263 return 0; 264 } 265 266 static void destroy_inodecache(void) 267 { 268 kmem_cache_destroy(adfs_inode_cachep); 269 } 270 271 static const struct super_operations adfs_sops = { 272 .alloc_inode = adfs_alloc_inode, 273 .destroy_inode = adfs_destroy_inode, 274 .write_inode = adfs_write_inode, 275 .put_super = adfs_put_super, 276 .statfs = adfs_statfs, 277 .remount_fs = adfs_remount, 278 .show_options = adfs_show_options, 279 }; 280 281 static struct adfs_discmap *adfs_read_map(struct super_block *sb, struct adfs_discrecord *dr) 282 { 283 struct adfs_discmap *dm; 284 unsigned int map_addr, zone_size, nzones; 285 int i, zone; 286 struct adfs_sb_info *asb = ADFS_SB(sb); 287 288 nzones = asb->s_map_size; 289 zone_size = (8 << dr->log2secsize) - le16_to_cpu(dr->zone_spare); 290 map_addr = (nzones >> 1) * zone_size - 291 ((nzones > 1) ? ADFS_DR_SIZE_BITS : 0); 292 map_addr = signed_asl(map_addr, asb->s_map2blk); 293 294 asb->s_ids_per_zone = zone_size / (asb->s_idlen + 1); 295 296 dm = kmalloc(nzones * sizeof(*dm), GFP_KERNEL); 297 if (dm == NULL) { 298 adfs_error(sb, "not enough memory"); 299 return NULL; 300 } 301 302 for (zone = 0; zone < nzones; zone++, map_addr++) { 303 dm[zone].dm_startbit = 0; 304 dm[zone].dm_endbit = zone_size; 305 dm[zone].dm_startblk = zone * zone_size - ADFS_DR_SIZE_BITS; 306 dm[zone].dm_bh = sb_bread(sb, map_addr); 307 308 if (!dm[zone].dm_bh) { 309 adfs_error(sb, "unable to read map"); 310 goto error_free; 311 } 312 } 313 314 /* adjust the limits for the first and last map zones */ 315 i = zone - 1; 316 dm[0].dm_startblk = 0; 317 dm[0].dm_startbit = ADFS_DR_SIZE_BITS; 318 dm[i].dm_endbit = (le32_to_cpu(dr->disc_size_high) << (32 - dr->log2bpmb)) + 319 (le32_to_cpu(dr->disc_size) >> dr->log2bpmb) + 320 (ADFS_DR_SIZE_BITS - i * zone_size); 321 322 if (adfs_checkmap(sb, dm)) 323 return dm; 324 325 adfs_error(sb, "map corrupted"); 326 327 error_free: 328 while (--zone >= 0) 329 brelse(dm[zone].dm_bh); 330 331 kfree(dm); 332 return NULL; 333 } 334 335 static inline unsigned long adfs_discsize(struct adfs_discrecord *dr, int block_bits) 336 { 337 unsigned long discsize; 338 339 discsize = le32_to_cpu(dr->disc_size_high) << (32 - block_bits); 340 discsize |= le32_to_cpu(dr->disc_size) >> block_bits; 341 342 return discsize; 343 } 344 345 static int adfs_fill_super(struct super_block *sb, void *data, int silent) 346 { 347 struct adfs_discrecord *dr; 348 struct buffer_head *bh; 349 struct object_info root_obj; 350 unsigned char *b_data; 351 struct adfs_sb_info *asb; 352 struct inode *root; 353 354 sb->s_flags |= MS_NODIRATIME; 355 356 asb = kzalloc(sizeof(*asb), GFP_KERNEL); 357 if (!asb) 358 return -ENOMEM; 359 sb->s_fs_info = asb; 360 361 /* set default options */ 362 asb->s_uid = 0; 363 asb->s_gid = 0; 364 asb->s_owner_mask = ADFS_DEFAULT_OWNER_MASK; 365 asb->s_other_mask = ADFS_DEFAULT_OTHER_MASK; 366 367 if (parse_options(sb, data)) 368 goto error; 369 370 sb_set_blocksize(sb, BLOCK_SIZE); 371 if (!(bh = sb_bread(sb, ADFS_DISCRECORD / BLOCK_SIZE))) { 372 adfs_error(sb, "unable to read superblock"); 373 goto error; 374 } 375 376 b_data = bh->b_data + (ADFS_DISCRECORD % BLOCK_SIZE); 377 378 if (adfs_checkbblk(b_data)) { 379 if (!silent) 380 printk("VFS: Can't find an adfs filesystem on dev " 381 "%s.\n", sb->s_id); 382 goto error_free_bh; 383 } 384 385 dr = (struct adfs_discrecord *)(b_data + ADFS_DR_OFFSET); 386 387 /* 388 * Do some sanity checks on the ADFS disc record 389 */ 390 if (adfs_checkdiscrecord(dr)) { 391 if (!silent) 392 printk("VPS: Can't find an adfs filesystem on dev " 393 "%s.\n", sb->s_id); 394 goto error_free_bh; 395 } 396 397 brelse(bh); 398 if (sb_set_blocksize(sb, 1 << dr->log2secsize)) { 399 bh = sb_bread(sb, ADFS_DISCRECORD / sb->s_blocksize); 400 if (!bh) { 401 adfs_error(sb, "couldn't read superblock on " 402 "2nd try."); 403 goto error; 404 } 405 b_data = bh->b_data + (ADFS_DISCRECORD % sb->s_blocksize); 406 if (adfs_checkbblk(b_data)) { 407 adfs_error(sb, "disc record mismatch, very weird!"); 408 goto error_free_bh; 409 } 410 dr = (struct adfs_discrecord *)(b_data + ADFS_DR_OFFSET); 411 } else { 412 if (!silent) 413 printk(KERN_ERR "VFS: Unsupported blocksize on dev " 414 "%s.\n", sb->s_id); 415 goto error; 416 } 417 418 /* 419 * blocksize on this device should now be set to the ADFS log2secsize 420 */ 421 422 sb->s_magic = ADFS_SUPER_MAGIC; 423 asb->s_idlen = dr->idlen; 424 asb->s_map_size = dr->nzones | (dr->nzones_high << 8); 425 asb->s_map2blk = dr->log2bpmb - dr->log2secsize; 426 asb->s_size = adfs_discsize(dr, sb->s_blocksize_bits); 427 asb->s_version = dr->format_version; 428 asb->s_log2sharesize = dr->log2sharesize; 429 430 asb->s_map = adfs_read_map(sb, dr); 431 if (!asb->s_map) 432 goto error_free_bh; 433 434 brelse(bh); 435 436 /* 437 * set up enough so that we can read an inode 438 */ 439 sb->s_op = &adfs_sops; 440 441 dr = (struct adfs_discrecord *)(asb->s_map[0].dm_bh->b_data + 4); 442 443 root_obj.parent_id = root_obj.file_id = le32_to_cpu(dr->root); 444 root_obj.name_len = 0; 445 root_obj.loadaddr = 0; 446 root_obj.execaddr = 0; 447 root_obj.size = ADFS_NEWDIR_SIZE; 448 root_obj.attr = ADFS_NDA_DIRECTORY | ADFS_NDA_OWNER_READ | 449 ADFS_NDA_OWNER_WRITE | ADFS_NDA_PUBLIC_READ; 450 451 /* 452 * If this is a F+ disk with variable length directories, 453 * get the root_size from the disc record. 454 */ 455 if (asb->s_version) { 456 root_obj.size = le32_to_cpu(dr->root_size); 457 asb->s_dir = &adfs_fplus_dir_ops; 458 asb->s_namelen = ADFS_FPLUS_NAME_LEN; 459 } else { 460 asb->s_dir = &adfs_f_dir_ops; 461 asb->s_namelen = ADFS_F_NAME_LEN; 462 } 463 464 root = adfs_iget(sb, &root_obj); 465 sb->s_root = d_alloc_root(root); 466 if (!sb->s_root) { 467 int i; 468 iput(root); 469 for (i = 0; i < asb->s_map_size; i++) 470 brelse(asb->s_map[i].dm_bh); 471 kfree(asb->s_map); 472 adfs_error(sb, "get root inode failed\n"); 473 goto error; 474 } else 475 sb->s_root->d_op = &adfs_dentry_operations; 476 return 0; 477 478 error_free_bh: 479 brelse(bh); 480 error: 481 sb->s_fs_info = NULL; 482 kfree(asb); 483 return -EINVAL; 484 } 485 486 static int adfs_get_sb(struct file_system_type *fs_type, 487 int flags, const char *dev_name, void *data, struct vfsmount *mnt) 488 { 489 return get_sb_bdev(fs_type, flags, dev_name, data, adfs_fill_super, 490 mnt); 491 } 492 493 static struct file_system_type adfs_fs_type = { 494 .owner = THIS_MODULE, 495 .name = "adfs", 496 .get_sb = adfs_get_sb, 497 .kill_sb = kill_block_super, 498 .fs_flags = FS_REQUIRES_DEV, 499 }; 500 501 static int __init init_adfs_fs(void) 502 { 503 int err = init_inodecache(); 504 if (err) 505 goto out1; 506 err = register_filesystem(&adfs_fs_type); 507 if (err) 508 goto out; 509 return 0; 510 out: 511 destroy_inodecache(); 512 out1: 513 return err; 514 } 515 516 static void __exit exit_adfs_fs(void) 517 { 518 unregister_filesystem(&adfs_fs_type); 519 destroy_inodecache(); 520 } 521 522 module_init(init_adfs_fs) 523 module_exit(exit_adfs_fs) 524 MODULE_LICENSE("GPL"); 525