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/smp_lock.h> 18 #include <linux/statfs.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 lock_kernel(); 124 125 for (i = 0; i < asb->s_map_size; i++) 126 brelse(asb->s_map[i].dm_bh); 127 kfree(asb->s_map); 128 kfree(asb); 129 sb->s_fs_info = NULL; 130 131 unlock_kernel(); 132 } 133 134 static int adfs_show_options(struct seq_file *seq, struct vfsmount *mnt) 135 { 136 struct adfs_sb_info *asb = ADFS_SB(mnt->mnt_sb); 137 138 if (asb->s_uid != 0) 139 seq_printf(seq, ",uid=%u", asb->s_uid); 140 if (asb->s_gid != 0) 141 seq_printf(seq, ",gid=%u", asb->s_gid); 142 if (asb->s_owner_mask != ADFS_DEFAULT_OWNER_MASK) 143 seq_printf(seq, ",ownmask=%o", asb->s_owner_mask); 144 if (asb->s_other_mask != ADFS_DEFAULT_OTHER_MASK) 145 seq_printf(seq, ",othmask=%o", asb->s_other_mask); 146 147 return 0; 148 } 149 150 enum {Opt_uid, Opt_gid, Opt_ownmask, Opt_othmask, Opt_err}; 151 152 static const match_table_t tokens = { 153 {Opt_uid, "uid=%u"}, 154 {Opt_gid, "gid=%u"}, 155 {Opt_ownmask, "ownmask=%o"}, 156 {Opt_othmask, "othmask=%o"}, 157 {Opt_err, NULL} 158 }; 159 160 static int parse_options(struct super_block *sb, char *options) 161 { 162 char *p; 163 struct adfs_sb_info *asb = ADFS_SB(sb); 164 int option; 165 166 if (!options) 167 return 0; 168 169 while ((p = strsep(&options, ",")) != NULL) { 170 substring_t args[MAX_OPT_ARGS]; 171 int token; 172 if (!*p) 173 continue; 174 175 token = match_token(p, tokens, args); 176 switch (token) { 177 case Opt_uid: 178 if (match_int(args, &option)) 179 return -EINVAL; 180 asb->s_uid = option; 181 break; 182 case Opt_gid: 183 if (match_int(args, &option)) 184 return -EINVAL; 185 asb->s_gid = option; 186 break; 187 case Opt_ownmask: 188 if (match_octal(args, &option)) 189 return -EINVAL; 190 asb->s_owner_mask = option; 191 break; 192 case Opt_othmask: 193 if (match_octal(args, &option)) 194 return -EINVAL; 195 asb->s_other_mask = option; 196 break; 197 default: 198 printk("ADFS-fs: unrecognised mount option \"%s\" " 199 "or missing value\n", p); 200 return -EINVAL; 201 } 202 } 203 return 0; 204 } 205 206 static int adfs_remount(struct super_block *sb, int *flags, char *data) 207 { 208 *flags |= MS_NODIRATIME; 209 return parse_options(sb, data); 210 } 211 212 static int adfs_statfs(struct dentry *dentry, struct kstatfs *buf) 213 { 214 struct super_block *sb = dentry->d_sb; 215 struct adfs_sb_info *sbi = ADFS_SB(sb); 216 u64 id = huge_encode_dev(sb->s_bdev->bd_dev); 217 218 buf->f_type = ADFS_SUPER_MAGIC; 219 buf->f_namelen = sbi->s_namelen; 220 buf->f_bsize = sb->s_blocksize; 221 buf->f_blocks = sbi->s_size; 222 buf->f_files = sbi->s_ids_per_zone * sbi->s_map_size; 223 buf->f_bavail = 224 buf->f_bfree = adfs_map_free(sb); 225 buf->f_ffree = (long)(buf->f_bfree * buf->f_files) / (long)buf->f_blocks; 226 buf->f_fsid.val[0] = (u32)id; 227 buf->f_fsid.val[1] = (u32)(id >> 32); 228 229 return 0; 230 } 231 232 static struct kmem_cache *adfs_inode_cachep; 233 234 static struct inode *adfs_alloc_inode(struct super_block *sb) 235 { 236 struct adfs_inode_info *ei; 237 ei = (struct adfs_inode_info *)kmem_cache_alloc(adfs_inode_cachep, GFP_KERNEL); 238 if (!ei) 239 return NULL; 240 return &ei->vfs_inode; 241 } 242 243 static void adfs_destroy_inode(struct inode *inode) 244 { 245 kmem_cache_free(adfs_inode_cachep, ADFS_I(inode)); 246 } 247 248 static void init_once(void *foo) 249 { 250 struct adfs_inode_info *ei = (struct adfs_inode_info *) foo; 251 252 inode_init_once(&ei->vfs_inode); 253 } 254 255 static int init_inodecache(void) 256 { 257 adfs_inode_cachep = kmem_cache_create("adfs_inode_cache", 258 sizeof(struct adfs_inode_info), 259 0, (SLAB_RECLAIM_ACCOUNT| 260 SLAB_MEM_SPREAD), 261 init_once); 262 if (adfs_inode_cachep == NULL) 263 return -ENOMEM; 264 return 0; 265 } 266 267 static void destroy_inodecache(void) 268 { 269 kmem_cache_destroy(adfs_inode_cachep); 270 } 271 272 static const struct super_operations adfs_sops = { 273 .alloc_inode = adfs_alloc_inode, 274 .destroy_inode = adfs_destroy_inode, 275 .write_inode = adfs_write_inode, 276 .put_super = adfs_put_super, 277 .statfs = adfs_statfs, 278 .remount_fs = adfs_remount, 279 .show_options = adfs_show_options, 280 }; 281 282 static struct adfs_discmap *adfs_read_map(struct super_block *sb, struct adfs_discrecord *dr) 283 { 284 struct adfs_discmap *dm; 285 unsigned int map_addr, zone_size, nzones; 286 int i, zone; 287 struct adfs_sb_info *asb = ADFS_SB(sb); 288 289 nzones = asb->s_map_size; 290 zone_size = (8 << dr->log2secsize) - le16_to_cpu(dr->zone_spare); 291 map_addr = (nzones >> 1) * zone_size - 292 ((nzones > 1) ? ADFS_DR_SIZE_BITS : 0); 293 map_addr = signed_asl(map_addr, asb->s_map2blk); 294 295 asb->s_ids_per_zone = zone_size / (asb->s_idlen + 1); 296 297 dm = kmalloc(nzones * sizeof(*dm), GFP_KERNEL); 298 if (dm == NULL) { 299 adfs_error(sb, "not enough memory"); 300 return NULL; 301 } 302 303 for (zone = 0; zone < nzones; zone++, map_addr++) { 304 dm[zone].dm_startbit = 0; 305 dm[zone].dm_endbit = zone_size; 306 dm[zone].dm_startblk = zone * zone_size - ADFS_DR_SIZE_BITS; 307 dm[zone].dm_bh = sb_bread(sb, map_addr); 308 309 if (!dm[zone].dm_bh) { 310 adfs_error(sb, "unable to read map"); 311 goto error_free; 312 } 313 } 314 315 /* adjust the limits for the first and last map zones */ 316 i = zone - 1; 317 dm[0].dm_startblk = 0; 318 dm[0].dm_startbit = ADFS_DR_SIZE_BITS; 319 dm[i].dm_endbit = (le32_to_cpu(dr->disc_size_high) << (32 - dr->log2bpmb)) + 320 (le32_to_cpu(dr->disc_size) >> dr->log2bpmb) + 321 (ADFS_DR_SIZE_BITS - i * zone_size); 322 323 if (adfs_checkmap(sb, dm)) 324 return dm; 325 326 adfs_error(sb, "map corrupted"); 327 328 error_free: 329 while (--zone >= 0) 330 brelse(dm[zone].dm_bh); 331 332 kfree(dm); 333 return NULL; 334 } 335 336 static inline unsigned long adfs_discsize(struct adfs_discrecord *dr, int block_bits) 337 { 338 unsigned long discsize; 339 340 discsize = le32_to_cpu(dr->disc_size_high) << (32 - block_bits); 341 discsize |= le32_to_cpu(dr->disc_size) >> block_bits; 342 343 return discsize; 344 } 345 346 static int adfs_fill_super(struct super_block *sb, void *data, int silent) 347 { 348 struct adfs_discrecord *dr; 349 struct buffer_head *bh; 350 struct object_info root_obj; 351 unsigned char *b_data; 352 struct adfs_sb_info *asb; 353 struct inode *root; 354 355 sb->s_flags |= MS_NODIRATIME; 356 357 asb = kzalloc(sizeof(*asb), GFP_KERNEL); 358 if (!asb) 359 return -ENOMEM; 360 sb->s_fs_info = asb; 361 362 /* set default options */ 363 asb->s_uid = 0; 364 asb->s_gid = 0; 365 asb->s_owner_mask = ADFS_DEFAULT_OWNER_MASK; 366 asb->s_other_mask = ADFS_DEFAULT_OTHER_MASK; 367 368 if (parse_options(sb, data)) 369 goto error; 370 371 sb_set_blocksize(sb, BLOCK_SIZE); 372 if (!(bh = sb_bread(sb, ADFS_DISCRECORD / BLOCK_SIZE))) { 373 adfs_error(sb, "unable to read superblock"); 374 goto error; 375 } 376 377 b_data = bh->b_data + (ADFS_DISCRECORD % BLOCK_SIZE); 378 379 if (adfs_checkbblk(b_data)) { 380 if (!silent) 381 printk("VFS: Can't find an adfs filesystem on dev " 382 "%s.\n", sb->s_id); 383 goto error_free_bh; 384 } 385 386 dr = (struct adfs_discrecord *)(b_data + ADFS_DR_OFFSET); 387 388 /* 389 * Do some sanity checks on the ADFS disc record 390 */ 391 if (adfs_checkdiscrecord(dr)) { 392 if (!silent) 393 printk("VPS: Can't find an adfs filesystem on dev " 394 "%s.\n", sb->s_id); 395 goto error_free_bh; 396 } 397 398 brelse(bh); 399 if (sb_set_blocksize(sb, 1 << dr->log2secsize)) { 400 bh = sb_bread(sb, ADFS_DISCRECORD / sb->s_blocksize); 401 if (!bh) { 402 adfs_error(sb, "couldn't read superblock on " 403 "2nd try."); 404 goto error; 405 } 406 b_data = bh->b_data + (ADFS_DISCRECORD % sb->s_blocksize); 407 if (adfs_checkbblk(b_data)) { 408 adfs_error(sb, "disc record mismatch, very weird!"); 409 goto error_free_bh; 410 } 411 dr = (struct adfs_discrecord *)(b_data + ADFS_DR_OFFSET); 412 } else { 413 if (!silent) 414 printk(KERN_ERR "VFS: Unsupported blocksize on dev " 415 "%s.\n", sb->s_id); 416 goto error; 417 } 418 419 /* 420 * blocksize on this device should now be set to the ADFS log2secsize 421 */ 422 423 sb->s_magic = ADFS_SUPER_MAGIC; 424 asb->s_idlen = dr->idlen; 425 asb->s_map_size = dr->nzones | (dr->nzones_high << 8); 426 asb->s_map2blk = dr->log2bpmb - dr->log2secsize; 427 asb->s_size = adfs_discsize(dr, sb->s_blocksize_bits); 428 asb->s_version = dr->format_version; 429 asb->s_log2sharesize = dr->log2sharesize; 430 431 asb->s_map = adfs_read_map(sb, dr); 432 if (!asb->s_map) 433 goto error_free_bh; 434 435 brelse(bh); 436 437 /* 438 * set up enough so that we can read an inode 439 */ 440 sb->s_op = &adfs_sops; 441 442 dr = (struct adfs_discrecord *)(asb->s_map[0].dm_bh->b_data + 4); 443 444 root_obj.parent_id = root_obj.file_id = le32_to_cpu(dr->root); 445 root_obj.name_len = 0; 446 root_obj.loadaddr = 0; 447 root_obj.execaddr = 0; 448 root_obj.size = ADFS_NEWDIR_SIZE; 449 root_obj.attr = ADFS_NDA_DIRECTORY | ADFS_NDA_OWNER_READ | 450 ADFS_NDA_OWNER_WRITE | ADFS_NDA_PUBLIC_READ; 451 452 /* 453 * If this is a F+ disk with variable length directories, 454 * get the root_size from the disc record. 455 */ 456 if (asb->s_version) { 457 root_obj.size = le32_to_cpu(dr->root_size); 458 asb->s_dir = &adfs_fplus_dir_ops; 459 asb->s_namelen = ADFS_FPLUS_NAME_LEN; 460 } else { 461 asb->s_dir = &adfs_f_dir_ops; 462 asb->s_namelen = ADFS_F_NAME_LEN; 463 } 464 465 root = adfs_iget(sb, &root_obj); 466 sb->s_root = d_alloc_root(root); 467 if (!sb->s_root) { 468 int i; 469 iput(root); 470 for (i = 0; i < asb->s_map_size; i++) 471 brelse(asb->s_map[i].dm_bh); 472 kfree(asb->s_map); 473 adfs_error(sb, "get root inode failed\n"); 474 goto error; 475 } else 476 sb->s_root->d_op = &adfs_dentry_operations; 477 return 0; 478 479 error_free_bh: 480 brelse(bh); 481 error: 482 sb->s_fs_info = NULL; 483 kfree(asb); 484 return -EINVAL; 485 } 486 487 static int adfs_get_sb(struct file_system_type *fs_type, 488 int flags, const char *dev_name, void *data, struct vfsmount *mnt) 489 { 490 return get_sb_bdev(fs_type, flags, dev_name, data, adfs_fill_super, 491 mnt); 492 } 493 494 static struct file_system_type adfs_fs_type = { 495 .owner = THIS_MODULE, 496 .name = "adfs", 497 .get_sb = adfs_get_sb, 498 .kill_sb = kill_block_super, 499 .fs_flags = FS_REQUIRES_DEV, 500 }; 501 502 static int __init init_adfs_fs(void) 503 { 504 int err = init_inodecache(); 505 if (err) 506 goto out1; 507 err = register_filesystem(&adfs_fs_type); 508 if (err) 509 goto out; 510 return 0; 511 out: 512 destroy_inodecache(); 513 out1: 514 return err; 515 } 516 517 static void __exit exit_adfs_fs(void) 518 { 519 unregister_filesystem(&adfs_fs_type); 520 destroy_inodecache(); 521 } 522 523 module_init(init_adfs_fs) 524 module_exit(exit_adfs_fs) 525 MODULE_LICENSE("GPL"); 526