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