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 vfsmount *mnt) 130 { 131 struct adfs_sb_info *asb = ADFS_SB(mnt->mnt_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); 141 142 return 0; 143 } 144 145 enum {Opt_uid, Opt_gid, Opt_ownmask, Opt_othmask, Opt_err}; 146 147 static const match_table_t tokens = { 148 {Opt_uid, "uid=%u"}, 149 {Opt_gid, "gid=%u"}, 150 {Opt_ownmask, "ownmask=%o"}, 151 {Opt_othmask, "othmask=%o"}, 152 {Opt_err, NULL} 153 }; 154 155 static int parse_options(struct super_block *sb, char *options) 156 { 157 char *p; 158 struct adfs_sb_info *asb = ADFS_SB(sb); 159 int option; 160 161 if (!options) 162 return 0; 163 164 while ((p = strsep(&options, ",")) != NULL) { 165 substring_t args[MAX_OPT_ARGS]; 166 int token; 167 if (!*p) 168 continue; 169 170 token = match_token(p, tokens, args); 171 switch (token) { 172 case Opt_uid: 173 if (match_int(args, &option)) 174 return -EINVAL; 175 asb->s_uid = option; 176 break; 177 case Opt_gid: 178 if (match_int(args, &option)) 179 return -EINVAL; 180 asb->s_gid = option; 181 break; 182 case Opt_ownmask: 183 if (match_octal(args, &option)) 184 return -EINVAL; 185 asb->s_owner_mask = option; 186 break; 187 case Opt_othmask: 188 if (match_octal(args, &option)) 189 return -EINVAL; 190 asb->s_other_mask = option; 191 break; 192 default: 193 printk("ADFS-fs: unrecognised mount option \"%s\" " 194 "or missing value\n", p); 195 return -EINVAL; 196 } 197 } 198 return 0; 199 } 200 201 static int adfs_remount(struct super_block *sb, int *flags, char *data) 202 { 203 *flags |= MS_NODIRATIME; 204 return parse_options(sb, data); 205 } 206 207 static int adfs_statfs(struct dentry *dentry, struct kstatfs *buf) 208 { 209 struct super_block *sb = dentry->d_sb; 210 struct adfs_sb_info *sbi = ADFS_SB(sb); 211 u64 id = huge_encode_dev(sb->s_bdev->bd_dev); 212 213 buf->f_type = ADFS_SUPER_MAGIC; 214 buf->f_namelen = sbi->s_namelen; 215 buf->f_bsize = sb->s_blocksize; 216 buf->f_blocks = sbi->s_size; 217 buf->f_files = sbi->s_ids_per_zone * sbi->s_map_size; 218 buf->f_bavail = 219 buf->f_bfree = adfs_map_free(sb); 220 buf->f_ffree = (long)(buf->f_bfree * buf->f_files) / (long)buf->f_blocks; 221 buf->f_fsid.val[0] = (u32)id; 222 buf->f_fsid.val[1] = (u32)(id >> 32); 223 224 return 0; 225 } 226 227 static struct kmem_cache *adfs_inode_cachep; 228 229 static struct inode *adfs_alloc_inode(struct super_block *sb) 230 { 231 struct adfs_inode_info *ei; 232 ei = (struct adfs_inode_info *)kmem_cache_alloc(adfs_inode_cachep, GFP_KERNEL); 233 if (!ei) 234 return NULL; 235 return &ei->vfs_inode; 236 } 237 238 static void adfs_i_callback(struct rcu_head *head) 239 { 240 struct inode *inode = container_of(head, struct inode, i_rcu); 241 INIT_LIST_HEAD(&inode->i_dentry); 242 kmem_cache_free(adfs_inode_cachep, ADFS_I(inode)); 243 } 244 245 static void adfs_destroy_inode(struct inode *inode) 246 { 247 call_rcu(&inode->i_rcu, adfs_i_callback); 248 } 249 250 static void init_once(void *foo) 251 { 252 struct adfs_inode_info *ei = (struct adfs_inode_info *) foo; 253 254 inode_init_once(&ei->vfs_inode); 255 } 256 257 static int init_inodecache(void) 258 { 259 adfs_inode_cachep = kmem_cache_create("adfs_inode_cache", 260 sizeof(struct adfs_inode_info), 261 0, (SLAB_RECLAIM_ACCOUNT| 262 SLAB_MEM_SPREAD), 263 init_once); 264 if (adfs_inode_cachep == NULL) 265 return -ENOMEM; 266 return 0; 267 } 268 269 static void destroy_inodecache(void) 270 { 271 kmem_cache_destroy(adfs_inode_cachep); 272 } 273 274 static const struct super_operations adfs_sops = { 275 .alloc_inode = adfs_alloc_inode, 276 .destroy_inode = adfs_destroy_inode, 277 .write_inode = adfs_write_inode, 278 .put_super = adfs_put_super, 279 .statfs = adfs_statfs, 280 .remount_fs = adfs_remount, 281 .show_options = adfs_show_options, 282 }; 283 284 static struct adfs_discmap *adfs_read_map(struct super_block *sb, struct adfs_discrecord *dr) 285 { 286 struct adfs_discmap *dm; 287 unsigned int map_addr, zone_size, nzones; 288 int i, zone; 289 struct adfs_sb_info *asb = ADFS_SB(sb); 290 291 nzones = asb->s_map_size; 292 zone_size = (8 << dr->log2secsize) - le16_to_cpu(dr->zone_spare); 293 map_addr = (nzones >> 1) * zone_size - 294 ((nzones > 1) ? ADFS_DR_SIZE_BITS : 0); 295 map_addr = signed_asl(map_addr, asb->s_map2blk); 296 297 asb->s_ids_per_zone = zone_size / (asb->s_idlen + 1); 298 299 dm = kmalloc(nzones * sizeof(*dm), GFP_KERNEL); 300 if (dm == NULL) { 301 adfs_error(sb, "not enough memory"); 302 return NULL; 303 } 304 305 for (zone = 0; zone < nzones; zone++, map_addr++) { 306 dm[zone].dm_startbit = 0; 307 dm[zone].dm_endbit = zone_size; 308 dm[zone].dm_startblk = zone * zone_size - ADFS_DR_SIZE_BITS; 309 dm[zone].dm_bh = sb_bread(sb, map_addr); 310 311 if (!dm[zone].dm_bh) { 312 adfs_error(sb, "unable to read map"); 313 goto error_free; 314 } 315 } 316 317 /* adjust the limits for the first and last map zones */ 318 i = zone - 1; 319 dm[0].dm_startblk = 0; 320 dm[0].dm_startbit = ADFS_DR_SIZE_BITS; 321 dm[i].dm_endbit = (le32_to_cpu(dr->disc_size_high) << (32 - dr->log2bpmb)) + 322 (le32_to_cpu(dr->disc_size) >> dr->log2bpmb) + 323 (ADFS_DR_SIZE_BITS - i * zone_size); 324 325 if (adfs_checkmap(sb, dm)) 326 return dm; 327 328 adfs_error(sb, "map corrupted"); 329 330 error_free: 331 while (--zone >= 0) 332 brelse(dm[zone].dm_bh); 333 334 kfree(dm); 335 return NULL; 336 } 337 338 static inline unsigned long adfs_discsize(struct adfs_discrecord *dr, int block_bits) 339 { 340 unsigned long discsize; 341 342 discsize = le32_to_cpu(dr->disc_size_high) << (32 - block_bits); 343 discsize |= le32_to_cpu(dr->disc_size) >> block_bits; 344 345 return discsize; 346 } 347 348 static int adfs_fill_super(struct super_block *sb, void *data, int silent) 349 { 350 struct adfs_discrecord *dr; 351 struct buffer_head *bh; 352 struct object_info root_obj; 353 unsigned char *b_data; 354 struct adfs_sb_info *asb; 355 struct inode *root; 356 357 sb->s_flags |= MS_NODIRATIME; 358 359 asb = kzalloc(sizeof(*asb), GFP_KERNEL); 360 if (!asb) 361 return -ENOMEM; 362 sb->s_fs_info = asb; 363 364 /* set default options */ 365 asb->s_uid = 0; 366 asb->s_gid = 0; 367 asb->s_owner_mask = ADFS_DEFAULT_OWNER_MASK; 368 asb->s_other_mask = ADFS_DEFAULT_OTHER_MASK; 369 370 if (parse_options(sb, data)) 371 goto error; 372 373 sb_set_blocksize(sb, BLOCK_SIZE); 374 if (!(bh = sb_bread(sb, ADFS_DISCRECORD / BLOCK_SIZE))) { 375 adfs_error(sb, "unable to read superblock"); 376 goto error; 377 } 378 379 b_data = bh->b_data + (ADFS_DISCRECORD % BLOCK_SIZE); 380 381 if (adfs_checkbblk(b_data)) { 382 if (!silent) 383 printk("VFS: Can't find an adfs filesystem on dev " 384 "%s.\n", sb->s_id); 385 goto error_free_bh; 386 } 387 388 dr = (struct adfs_discrecord *)(b_data + ADFS_DR_OFFSET); 389 390 /* 391 * Do some sanity checks on the ADFS disc record 392 */ 393 if (adfs_checkdiscrecord(dr)) { 394 if (!silent) 395 printk("VPS: Can't find an adfs filesystem on dev " 396 "%s.\n", sb->s_id); 397 goto error_free_bh; 398 } 399 400 brelse(bh); 401 if (sb_set_blocksize(sb, 1 << dr->log2secsize)) { 402 bh = sb_bread(sb, ADFS_DISCRECORD / sb->s_blocksize); 403 if (!bh) { 404 adfs_error(sb, "couldn't read superblock on " 405 "2nd try."); 406 goto error; 407 } 408 b_data = bh->b_data + (ADFS_DISCRECORD % sb->s_blocksize); 409 if (adfs_checkbblk(b_data)) { 410 adfs_error(sb, "disc record mismatch, very weird!"); 411 goto error_free_bh; 412 } 413 dr = (struct adfs_discrecord *)(b_data + ADFS_DR_OFFSET); 414 } else { 415 if (!silent) 416 printk(KERN_ERR "VFS: Unsupported blocksize on dev " 417 "%s.\n", sb->s_id); 418 goto error; 419 } 420 421 /* 422 * blocksize on this device should now be set to the ADFS log2secsize 423 */ 424 425 sb->s_magic = ADFS_SUPER_MAGIC; 426 asb->s_idlen = dr->idlen; 427 asb->s_map_size = dr->nzones | (dr->nzones_high << 8); 428 asb->s_map2blk = dr->log2bpmb - dr->log2secsize; 429 asb->s_size = adfs_discsize(dr, sb->s_blocksize_bits); 430 asb->s_version = dr->format_version; 431 asb->s_log2sharesize = dr->log2sharesize; 432 433 asb->s_map = adfs_read_map(sb, dr); 434 if (!asb->s_map) 435 goto error_free_bh; 436 437 brelse(bh); 438 439 /* 440 * set up enough so that we can read an inode 441 */ 442 sb->s_op = &adfs_sops; 443 444 dr = (struct adfs_discrecord *)(asb->s_map[0].dm_bh->b_data + 4); 445 446 root_obj.parent_id = root_obj.file_id = le32_to_cpu(dr->root); 447 root_obj.name_len = 0; 448 root_obj.loadaddr = 0; 449 root_obj.execaddr = 0; 450 root_obj.size = ADFS_NEWDIR_SIZE; 451 root_obj.attr = ADFS_NDA_DIRECTORY | ADFS_NDA_OWNER_READ | 452 ADFS_NDA_OWNER_WRITE | ADFS_NDA_PUBLIC_READ; 453 454 /* 455 * If this is a F+ disk with variable length directories, 456 * get the root_size from the disc record. 457 */ 458 if (asb->s_version) { 459 root_obj.size = le32_to_cpu(dr->root_size); 460 asb->s_dir = &adfs_fplus_dir_ops; 461 asb->s_namelen = ADFS_FPLUS_NAME_LEN; 462 } else { 463 asb->s_dir = &adfs_f_dir_ops; 464 asb->s_namelen = ADFS_F_NAME_LEN; 465 } 466 467 sb->s_d_op = &adfs_dentry_operations; 468 root = adfs_iget(sb, &root_obj); 469 sb->s_root = d_alloc_root(root); 470 if (!sb->s_root) { 471 int i; 472 iput(root); 473 for (i = 0; i < asb->s_map_size; i++) 474 brelse(asb->s_map[i].dm_bh); 475 kfree(asb->s_map); 476 adfs_error(sb, "get root inode failed\n"); 477 goto error; 478 } 479 return 0; 480 481 error_free_bh: 482 brelse(bh); 483 error: 484 sb->s_fs_info = NULL; 485 kfree(asb); 486 return -EINVAL; 487 } 488 489 static struct dentry *adfs_mount(struct file_system_type *fs_type, 490 int flags, const char *dev_name, void *data) 491 { 492 return mount_bdev(fs_type, flags, dev_name, data, adfs_fill_super); 493 } 494 495 static struct file_system_type adfs_fs_type = { 496 .owner = THIS_MODULE, 497 .name = "adfs", 498 .mount = adfs_mount, 499 .kill_sb = kill_block_super, 500 .fs_flags = FS_REQUIRES_DEV, 501 }; 502 503 static int __init init_adfs_fs(void) 504 { 505 int err = init_inodecache(); 506 if (err) 507 goto out1; 508 err = register_filesystem(&adfs_fs_type); 509 if (err) 510 goto out; 511 return 0; 512 out: 513 destroy_inodecache(); 514 out1: 515 return err; 516 } 517 518 static void __exit exit_adfs_fs(void) 519 { 520 unregister_filesystem(&adfs_fs_type); 521 destroy_inodecache(); 522 } 523 524 module_init(init_adfs_fs) 525 module_exit(exit_adfs_fs) 526 MODULE_LICENSE("GPL"); 527