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 for (i = 0; i < asb->s_map_size; i++) 136 brelse(asb->s_map[i].dm_bh); 137 kfree(asb->s_map); 138 kfree(asb); 139 sb->s_fs_info = NULL; 140 } 141 142 static int adfs_show_options(struct seq_file *seq, struct vfsmount *mnt) 143 { 144 struct adfs_sb_info *asb = ADFS_SB(mnt->mnt_sb); 145 146 if (asb->s_uid != 0) 147 seq_printf(seq, ",uid=%u", asb->s_uid); 148 if (asb->s_gid != 0) 149 seq_printf(seq, ",gid=%u", asb->s_gid); 150 if (asb->s_owner_mask != ADFS_DEFAULT_OWNER_MASK) 151 seq_printf(seq, ",ownmask=%o", asb->s_owner_mask); 152 if (asb->s_other_mask != ADFS_DEFAULT_OTHER_MASK) 153 seq_printf(seq, ",othmask=%o", asb->s_other_mask); 154 155 return 0; 156 } 157 158 enum {Opt_uid, Opt_gid, Opt_ownmask, Opt_othmask, Opt_err}; 159 160 static const match_table_t tokens = { 161 {Opt_uid, "uid=%u"}, 162 {Opt_gid, "gid=%u"}, 163 {Opt_ownmask, "ownmask=%o"}, 164 {Opt_othmask, "othmask=%o"}, 165 {Opt_err, NULL} 166 }; 167 168 static int parse_options(struct super_block *sb, char *options) 169 { 170 char *p; 171 struct adfs_sb_info *asb = ADFS_SB(sb); 172 int option; 173 174 if (!options) 175 return 0; 176 177 while ((p = strsep(&options, ",")) != NULL) { 178 substring_t args[MAX_OPT_ARGS]; 179 int token; 180 if (!*p) 181 continue; 182 183 token = match_token(p, tokens, args); 184 switch (token) { 185 case Opt_uid: 186 if (match_int(args, &option)) 187 return -EINVAL; 188 asb->s_uid = option; 189 break; 190 case Opt_gid: 191 if (match_int(args, &option)) 192 return -EINVAL; 193 asb->s_gid = option; 194 break; 195 case Opt_ownmask: 196 if (match_octal(args, &option)) 197 return -EINVAL; 198 asb->s_owner_mask = option; 199 break; 200 case Opt_othmask: 201 if (match_octal(args, &option)) 202 return -EINVAL; 203 asb->s_other_mask = option; 204 break; 205 default: 206 printk("ADFS-fs: unrecognised mount option \"%s\" " 207 "or missing value\n", p); 208 return -EINVAL; 209 } 210 } 211 return 0; 212 } 213 214 static int adfs_remount(struct super_block *sb, int *flags, char *data) 215 { 216 *flags |= MS_NODIRATIME; 217 return parse_options(sb, data); 218 } 219 220 static int adfs_statfs(struct dentry *dentry, struct kstatfs *buf) 221 { 222 struct super_block *sb = dentry->d_sb; 223 struct adfs_sb_info *sbi = ADFS_SB(sb); 224 u64 id = huge_encode_dev(sb->s_bdev->bd_dev); 225 226 buf->f_type = ADFS_SUPER_MAGIC; 227 buf->f_namelen = sbi->s_namelen; 228 buf->f_bsize = sb->s_blocksize; 229 buf->f_blocks = sbi->s_size; 230 buf->f_files = sbi->s_ids_per_zone * sbi->s_map_size; 231 buf->f_bavail = 232 buf->f_bfree = adfs_map_free(sb); 233 buf->f_ffree = (long)(buf->f_bfree * buf->f_files) / (long)buf->f_blocks; 234 buf->f_fsid.val[0] = (u32)id; 235 buf->f_fsid.val[1] = (u32)(id >> 32); 236 237 return 0; 238 } 239 240 static struct kmem_cache *adfs_inode_cachep; 241 242 static struct inode *adfs_alloc_inode(struct super_block *sb) 243 { 244 struct adfs_inode_info *ei; 245 ei = (struct adfs_inode_info *)kmem_cache_alloc(adfs_inode_cachep, GFP_KERNEL); 246 if (!ei) 247 return NULL; 248 return &ei->vfs_inode; 249 } 250 251 static void adfs_destroy_inode(struct inode *inode) 252 { 253 kmem_cache_free(adfs_inode_cachep, ADFS_I(inode)); 254 } 255 256 static void init_once(void *foo) 257 { 258 struct adfs_inode_info *ei = (struct adfs_inode_info *) foo; 259 260 inode_init_once(&ei->vfs_inode); 261 } 262 263 static int init_inodecache(void) 264 { 265 adfs_inode_cachep = kmem_cache_create("adfs_inode_cache", 266 sizeof(struct adfs_inode_info), 267 0, (SLAB_RECLAIM_ACCOUNT| 268 SLAB_MEM_SPREAD), 269 init_once); 270 if (adfs_inode_cachep == NULL) 271 return -ENOMEM; 272 return 0; 273 } 274 275 static void destroy_inodecache(void) 276 { 277 kmem_cache_destroy(adfs_inode_cachep); 278 } 279 280 static const struct super_operations adfs_sops = { 281 .alloc_inode = adfs_alloc_inode, 282 .destroy_inode = adfs_destroy_inode, 283 .write_inode = adfs_write_inode, 284 .put_super = adfs_put_super, 285 .statfs = adfs_statfs, 286 .remount_fs = adfs_remount, 287 .show_options = adfs_show_options, 288 }; 289 290 static struct adfs_discmap *adfs_read_map(struct super_block *sb, struct adfs_discrecord *dr) 291 { 292 struct adfs_discmap *dm; 293 unsigned int map_addr, zone_size, nzones; 294 int i, zone; 295 struct adfs_sb_info *asb = ADFS_SB(sb); 296 297 nzones = asb->s_map_size; 298 zone_size = (8 << dr->log2secsize) - le16_to_cpu(dr->zone_spare); 299 map_addr = (nzones >> 1) * zone_size - 300 ((nzones > 1) ? ADFS_DR_SIZE_BITS : 0); 301 map_addr = signed_asl(map_addr, asb->s_map2blk); 302 303 asb->s_ids_per_zone = zone_size / (asb->s_idlen + 1); 304 305 dm = kmalloc(nzones * sizeof(*dm), GFP_KERNEL); 306 if (dm == NULL) { 307 adfs_error(sb, "not enough memory"); 308 return NULL; 309 } 310 311 for (zone = 0; zone < nzones; zone++, map_addr++) { 312 dm[zone].dm_startbit = 0; 313 dm[zone].dm_endbit = zone_size; 314 dm[zone].dm_startblk = zone * zone_size - ADFS_DR_SIZE_BITS; 315 dm[zone].dm_bh = sb_bread(sb, map_addr); 316 317 if (!dm[zone].dm_bh) { 318 adfs_error(sb, "unable to read map"); 319 goto error_free; 320 } 321 } 322 323 /* adjust the limits for the first and last map zones */ 324 i = zone - 1; 325 dm[0].dm_startblk = 0; 326 dm[0].dm_startbit = ADFS_DR_SIZE_BITS; 327 dm[i].dm_endbit = (le32_to_cpu(dr->disc_size_high) << (32 - dr->log2bpmb)) + 328 (le32_to_cpu(dr->disc_size) >> dr->log2bpmb) + 329 (ADFS_DR_SIZE_BITS - i * zone_size); 330 331 if (adfs_checkmap(sb, dm)) 332 return dm; 333 334 adfs_error(sb, "map corrupted"); 335 336 error_free: 337 while (--zone >= 0) 338 brelse(dm[zone].dm_bh); 339 340 kfree(dm); 341 return NULL; 342 } 343 344 static inline unsigned long adfs_discsize(struct adfs_discrecord *dr, int block_bits) 345 { 346 unsigned long discsize; 347 348 discsize = le32_to_cpu(dr->disc_size_high) << (32 - block_bits); 349 discsize |= le32_to_cpu(dr->disc_size) >> block_bits; 350 351 return discsize; 352 } 353 354 static int adfs_fill_super(struct super_block *sb, void *data, int silent) 355 { 356 struct adfs_discrecord *dr; 357 struct buffer_head *bh; 358 struct object_info root_obj; 359 unsigned char *b_data; 360 struct adfs_sb_info *asb; 361 struct inode *root; 362 363 sb->s_flags |= MS_NODIRATIME; 364 365 asb = kzalloc(sizeof(*asb), GFP_KERNEL); 366 if (!asb) 367 return -ENOMEM; 368 sb->s_fs_info = asb; 369 370 /* set default options */ 371 asb->s_uid = 0; 372 asb->s_gid = 0; 373 asb->s_owner_mask = ADFS_DEFAULT_OWNER_MASK; 374 asb->s_other_mask = ADFS_DEFAULT_OTHER_MASK; 375 376 if (parse_options(sb, data)) 377 goto error; 378 379 sb_set_blocksize(sb, BLOCK_SIZE); 380 if (!(bh = sb_bread(sb, ADFS_DISCRECORD / BLOCK_SIZE))) { 381 adfs_error(sb, "unable to read superblock"); 382 goto error; 383 } 384 385 b_data = bh->b_data + (ADFS_DISCRECORD % BLOCK_SIZE); 386 387 if (adfs_checkbblk(b_data)) { 388 if (!silent) 389 printk("VFS: Can't find an adfs filesystem on dev " 390 "%s.\n", sb->s_id); 391 goto error_free_bh; 392 } 393 394 dr = (struct adfs_discrecord *)(b_data + ADFS_DR_OFFSET); 395 396 /* 397 * Do some sanity checks on the ADFS disc record 398 */ 399 if (adfs_checkdiscrecord(dr)) { 400 if (!silent) 401 printk("VPS: Can't find an adfs filesystem on dev " 402 "%s.\n", sb->s_id); 403 goto error_free_bh; 404 } 405 406 brelse(bh); 407 if (sb_set_blocksize(sb, 1 << dr->log2secsize)) { 408 bh = sb_bread(sb, ADFS_DISCRECORD / sb->s_blocksize); 409 if (!bh) { 410 adfs_error(sb, "couldn't read superblock on " 411 "2nd try."); 412 goto error; 413 } 414 b_data = bh->b_data + (ADFS_DISCRECORD % sb->s_blocksize); 415 if (adfs_checkbblk(b_data)) { 416 adfs_error(sb, "disc record mismatch, very weird!"); 417 goto error_free_bh; 418 } 419 dr = (struct adfs_discrecord *)(b_data + ADFS_DR_OFFSET); 420 } else { 421 if (!silent) 422 printk(KERN_ERR "VFS: Unsupported blocksize on dev " 423 "%s.\n", sb->s_id); 424 goto error; 425 } 426 427 /* 428 * blocksize on this device should now be set to the ADFS log2secsize 429 */ 430 431 sb->s_magic = ADFS_SUPER_MAGIC; 432 asb->s_idlen = dr->idlen; 433 asb->s_map_size = dr->nzones | (dr->nzones_high << 8); 434 asb->s_map2blk = dr->log2bpmb - dr->log2secsize; 435 asb->s_size = adfs_discsize(dr, sb->s_blocksize_bits); 436 asb->s_version = dr->format_version; 437 asb->s_log2sharesize = dr->log2sharesize; 438 439 asb->s_map = adfs_read_map(sb, dr); 440 if (!asb->s_map) 441 goto error_free_bh; 442 443 brelse(bh); 444 445 /* 446 * set up enough so that we can read an inode 447 */ 448 sb->s_op = &adfs_sops; 449 450 dr = (struct adfs_discrecord *)(asb->s_map[0].dm_bh->b_data + 4); 451 452 root_obj.parent_id = root_obj.file_id = le32_to_cpu(dr->root); 453 root_obj.name_len = 0; 454 root_obj.loadaddr = 0; 455 root_obj.execaddr = 0; 456 root_obj.size = ADFS_NEWDIR_SIZE; 457 root_obj.attr = ADFS_NDA_DIRECTORY | ADFS_NDA_OWNER_READ | 458 ADFS_NDA_OWNER_WRITE | ADFS_NDA_PUBLIC_READ; 459 460 /* 461 * If this is a F+ disk with variable length directories, 462 * get the root_size from the disc record. 463 */ 464 if (asb->s_version) { 465 root_obj.size = le32_to_cpu(dr->root_size); 466 asb->s_dir = &adfs_fplus_dir_ops; 467 asb->s_namelen = ADFS_FPLUS_NAME_LEN; 468 } else { 469 asb->s_dir = &adfs_f_dir_ops; 470 asb->s_namelen = ADFS_F_NAME_LEN; 471 } 472 473 root = adfs_iget(sb, &root_obj); 474 sb->s_root = d_alloc_root(root); 475 if (!sb->s_root) { 476 int i; 477 iput(root); 478 for (i = 0; i < asb->s_map_size; i++) 479 brelse(asb->s_map[i].dm_bh); 480 kfree(asb->s_map); 481 adfs_error(sb, "get root inode failed\n"); 482 goto error; 483 } else 484 sb->s_root->d_op = &adfs_dentry_operations; 485 return 0; 486 487 error_free_bh: 488 brelse(bh); 489 error: 490 sb->s_fs_info = NULL; 491 kfree(asb); 492 return -EINVAL; 493 } 494 495 static int adfs_get_sb(struct file_system_type *fs_type, 496 int flags, const char *dev_name, void *data, struct vfsmount *mnt) 497 { 498 return get_sb_bdev(fs_type, flags, dev_name, data, adfs_fill_super, 499 mnt); 500 } 501 502 static struct file_system_type adfs_fs_type = { 503 .owner = THIS_MODULE, 504 .name = "adfs", 505 .get_sb = adfs_get_sb, 506 .kill_sb = kill_block_super, 507 .fs_flags = FS_REQUIRES_DEV, 508 }; 509 510 static int __init init_adfs_fs(void) 511 { 512 int err = init_inodecache(); 513 if (err) 514 goto out1; 515 err = register_filesystem(&adfs_fs_type); 516 if (err) 517 goto out; 518 return 0; 519 out: 520 destroy_inodecache(); 521 out1: 522 return err; 523 } 524 525 static void __exit exit_adfs_fs(void) 526 { 527 unregister_filesystem(&adfs_fs_type); 528 destroy_inodecache(); 529 } 530 531 module_init(init_adfs_fs) 532 module_exit(exit_adfs_fs) 533