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 24 #include <asm/uaccess.h> 25 #include <asm/system.h> 26 27 #include <stdarg.h> 28 29 #include "adfs.h" 30 #include "dir_f.h" 31 #include "dir_fplus.h" 32 33 void __adfs_error(struct super_block *sb, const char *function, const char *fmt, ...) 34 { 35 char error_buf[128]; 36 va_list args; 37 38 va_start(args, fmt); 39 vsnprintf(error_buf, sizeof(error_buf), fmt, args); 40 va_end(args); 41 42 printk(KERN_CRIT "ADFS-fs error (device %s)%s%s: %s\n", 43 sb->s_id, function ? ": " : "", 44 function ? function : "", error_buf); 45 } 46 47 static int adfs_checkdiscrecord(struct adfs_discrecord *dr) 48 { 49 int i; 50 51 /* sector size must be 256, 512 or 1024 bytes */ 52 if (dr->log2secsize != 8 && 53 dr->log2secsize != 9 && 54 dr->log2secsize != 10) 55 return 1; 56 57 /* idlen must be at least log2secsize + 3 */ 58 if (dr->idlen < dr->log2secsize + 3) 59 return 1; 60 61 /* we cannot have such a large disc that we 62 * are unable to represent sector offsets in 63 * 32 bits. This works out at 2.0 TB. 64 */ 65 if (le32_to_cpu(dr->disc_size_high) >> dr->log2secsize) 66 return 1; 67 68 /* idlen must be no greater than 19 v2 [1.0] */ 69 if (dr->idlen > 19) 70 return 1; 71 72 /* reserved bytes should be zero */ 73 for (i = 0; i < sizeof(dr->unused52); i++) 74 if (dr->unused52[i] != 0) 75 return 1; 76 77 return 0; 78 } 79 80 static unsigned char adfs_calczonecheck(struct super_block *sb, unsigned char *map) 81 { 82 unsigned int v0, v1, v2, v3; 83 int i; 84 85 v0 = v1 = v2 = v3 = 0; 86 for (i = sb->s_blocksize - 4; i; i -= 4) { 87 v0 += map[i] + (v3 >> 8); 88 v3 &= 0xff; 89 v1 += map[i + 1] + (v0 >> 8); 90 v0 &= 0xff; 91 v2 += map[i + 2] + (v1 >> 8); 92 v1 &= 0xff; 93 v3 += map[i + 3] + (v2 >> 8); 94 v2 &= 0xff; 95 } 96 v0 += v3 >> 8; 97 v1 += map[1] + (v0 >> 8); 98 v2 += map[2] + (v1 >> 8); 99 v3 += map[3] + (v2 >> 8); 100 101 return v0 ^ v1 ^ v2 ^ v3; 102 } 103 104 static int adfs_checkmap(struct super_block *sb, struct adfs_discmap *dm) 105 { 106 unsigned char crosscheck = 0, zonecheck = 1; 107 int i; 108 109 for (i = 0; i < ADFS_SB(sb)->s_map_size; i++) { 110 unsigned char *map; 111 112 map = dm[i].dm_bh->b_data; 113 114 if (adfs_calczonecheck(sb, map) != map[0]) { 115 adfs_error(sb, "zone %d fails zonecheck", i); 116 zonecheck = 0; 117 } 118 crosscheck ^= map[3]; 119 } 120 if (crosscheck != 0xff) 121 adfs_error(sb, "crosscheck != 0xff"); 122 return crosscheck == 0xff && zonecheck; 123 } 124 125 static void adfs_put_super(struct super_block *sb) 126 { 127 int i; 128 struct adfs_sb_info *asb = ADFS_SB(sb); 129 130 for (i = 0; i < asb->s_map_size; i++) 131 brelse(asb->s_map[i].dm_bh); 132 kfree(asb->s_map); 133 kfree(asb); 134 sb->s_fs_info = NULL; 135 } 136 137 enum {Opt_uid, Opt_gid, Opt_ownmask, Opt_othmask, Opt_err}; 138 139 static match_table_t tokens = { 140 {Opt_uid, "uid=%u"}, 141 {Opt_gid, "gid=%u"}, 142 {Opt_ownmask, "ownmask=%o"}, 143 {Opt_othmask, "othmask=%o"}, 144 {Opt_err, NULL} 145 }; 146 147 static int parse_options(struct super_block *sb, char *options) 148 { 149 char *p; 150 struct adfs_sb_info *asb = ADFS_SB(sb); 151 int option; 152 153 if (!options) 154 return 0; 155 156 while ((p = strsep(&options, ",")) != NULL) { 157 substring_t args[MAX_OPT_ARGS]; 158 int token; 159 if (!*p) 160 continue; 161 162 token = match_token(p, tokens, args); 163 switch (token) { 164 case Opt_uid: 165 if (match_int(args, &option)) 166 return -EINVAL; 167 asb->s_uid = option; 168 break; 169 case Opt_gid: 170 if (match_int(args, &option)) 171 return -EINVAL; 172 asb->s_gid = option; 173 break; 174 case Opt_ownmask: 175 if (match_octal(args, &option)) 176 return -EINVAL; 177 asb->s_owner_mask = option; 178 break; 179 case Opt_othmask: 180 if (match_octal(args, &option)) 181 return -EINVAL; 182 asb->s_other_mask = option; 183 break; 184 default: 185 printk("ADFS-fs: unrecognised mount option \"%s\" " 186 "or missing value\n", p); 187 return -EINVAL; 188 } 189 } 190 return 0; 191 } 192 193 static int adfs_remount(struct super_block *sb, int *flags, char *data) 194 { 195 *flags |= MS_NODIRATIME; 196 return parse_options(sb, data); 197 } 198 199 static int adfs_statfs(struct dentry *dentry, struct kstatfs *buf) 200 { 201 struct adfs_sb_info *asb = ADFS_SB(dentry->d_sb); 202 203 buf->f_type = ADFS_SUPER_MAGIC; 204 buf->f_namelen = asb->s_namelen; 205 buf->f_bsize = dentry->d_sb->s_blocksize; 206 buf->f_blocks = asb->s_size; 207 buf->f_files = asb->s_ids_per_zone * asb->s_map_size; 208 buf->f_bavail = 209 buf->f_bfree = adfs_map_free(dentry->d_sb); 210 buf->f_ffree = (long)(buf->f_bfree * buf->f_files) / (long)buf->f_blocks; 211 212 return 0; 213 } 214 215 static struct kmem_cache *adfs_inode_cachep; 216 217 static struct inode *adfs_alloc_inode(struct super_block *sb) 218 { 219 struct adfs_inode_info *ei; 220 ei = (struct adfs_inode_info *)kmem_cache_alloc(adfs_inode_cachep, GFP_KERNEL); 221 if (!ei) 222 return NULL; 223 return &ei->vfs_inode; 224 } 225 226 static void adfs_destroy_inode(struct inode *inode) 227 { 228 kmem_cache_free(adfs_inode_cachep, ADFS_I(inode)); 229 } 230 231 static void init_once(void * foo, struct kmem_cache * cachep, unsigned long flags) 232 { 233 struct adfs_inode_info *ei = (struct adfs_inode_info *) foo; 234 235 if (flags & SLAB_CTOR_CONSTRUCTOR) 236 inode_init_once(&ei->vfs_inode); 237 } 238 239 static int init_inodecache(void) 240 { 241 adfs_inode_cachep = kmem_cache_create("adfs_inode_cache", 242 sizeof(struct adfs_inode_info), 243 0, (SLAB_RECLAIM_ACCOUNT| 244 SLAB_MEM_SPREAD), 245 init_once, NULL); 246 if (adfs_inode_cachep == NULL) 247 return -ENOMEM; 248 return 0; 249 } 250 251 static void destroy_inodecache(void) 252 { 253 kmem_cache_destroy(adfs_inode_cachep); 254 } 255 256 static const struct super_operations adfs_sops = { 257 .alloc_inode = adfs_alloc_inode, 258 .destroy_inode = adfs_destroy_inode, 259 .write_inode = adfs_write_inode, 260 .put_super = adfs_put_super, 261 .statfs = adfs_statfs, 262 .remount_fs = adfs_remount, 263 }; 264 265 static struct adfs_discmap *adfs_read_map(struct super_block *sb, struct adfs_discrecord *dr) 266 { 267 struct adfs_discmap *dm; 268 unsigned int map_addr, zone_size, nzones; 269 int i, zone; 270 struct adfs_sb_info *asb = ADFS_SB(sb); 271 272 nzones = asb->s_map_size; 273 zone_size = (8 << dr->log2secsize) - le16_to_cpu(dr->zone_spare); 274 map_addr = (nzones >> 1) * zone_size - 275 ((nzones > 1) ? ADFS_DR_SIZE_BITS : 0); 276 map_addr = signed_asl(map_addr, asb->s_map2blk); 277 278 asb->s_ids_per_zone = zone_size / (asb->s_idlen + 1); 279 280 dm = kmalloc(nzones * sizeof(*dm), GFP_KERNEL); 281 if (dm == NULL) { 282 adfs_error(sb, "not enough memory"); 283 return NULL; 284 } 285 286 for (zone = 0; zone < nzones; zone++, map_addr++) { 287 dm[zone].dm_startbit = 0; 288 dm[zone].dm_endbit = zone_size; 289 dm[zone].dm_startblk = zone * zone_size - ADFS_DR_SIZE_BITS; 290 dm[zone].dm_bh = sb_bread(sb, map_addr); 291 292 if (!dm[zone].dm_bh) { 293 adfs_error(sb, "unable to read map"); 294 goto error_free; 295 } 296 } 297 298 /* adjust the limits for the first and last map zones */ 299 i = zone - 1; 300 dm[0].dm_startblk = 0; 301 dm[0].dm_startbit = ADFS_DR_SIZE_BITS; 302 dm[i].dm_endbit = (le32_to_cpu(dr->disc_size_high) << (32 - dr->log2bpmb)) + 303 (le32_to_cpu(dr->disc_size) >> dr->log2bpmb) + 304 (ADFS_DR_SIZE_BITS - i * zone_size); 305 306 if (adfs_checkmap(sb, dm)) 307 return dm; 308 309 adfs_error(sb, "map corrupted"); 310 311 error_free: 312 while (--zone >= 0) 313 brelse(dm[zone].dm_bh); 314 315 kfree(dm); 316 return NULL; 317 } 318 319 static inline unsigned long adfs_discsize(struct adfs_discrecord *dr, int block_bits) 320 { 321 unsigned long discsize; 322 323 discsize = le32_to_cpu(dr->disc_size_high) << (32 - block_bits); 324 discsize |= le32_to_cpu(dr->disc_size) >> block_bits; 325 326 return discsize; 327 } 328 329 static int adfs_fill_super(struct super_block *sb, void *data, int silent) 330 { 331 struct adfs_discrecord *dr; 332 struct buffer_head *bh; 333 struct object_info root_obj; 334 unsigned char *b_data; 335 struct adfs_sb_info *asb; 336 struct inode *root; 337 338 sb->s_flags |= MS_NODIRATIME; 339 340 asb = kzalloc(sizeof(*asb), GFP_KERNEL); 341 if (!asb) 342 return -ENOMEM; 343 sb->s_fs_info = asb; 344 345 /* set default options */ 346 asb->s_uid = 0; 347 asb->s_gid = 0; 348 asb->s_owner_mask = S_IRWXU; 349 asb->s_other_mask = S_IRWXG | S_IRWXO; 350 351 if (parse_options(sb, data)) 352 goto error; 353 354 sb_set_blocksize(sb, BLOCK_SIZE); 355 if (!(bh = sb_bread(sb, ADFS_DISCRECORD / BLOCK_SIZE))) { 356 adfs_error(sb, "unable to read superblock"); 357 goto error; 358 } 359 360 b_data = bh->b_data + (ADFS_DISCRECORD % BLOCK_SIZE); 361 362 if (adfs_checkbblk(b_data)) { 363 if (!silent) 364 printk("VFS: Can't find an adfs filesystem on dev " 365 "%s.\n", sb->s_id); 366 goto error_free_bh; 367 } 368 369 dr = (struct adfs_discrecord *)(b_data + ADFS_DR_OFFSET); 370 371 /* 372 * Do some sanity checks on the ADFS disc record 373 */ 374 if (adfs_checkdiscrecord(dr)) { 375 if (!silent) 376 printk("VPS: Can't find an adfs filesystem on dev " 377 "%s.\n", sb->s_id); 378 goto error_free_bh; 379 } 380 381 brelse(bh); 382 if (sb_set_blocksize(sb, 1 << dr->log2secsize)) { 383 bh = sb_bread(sb, ADFS_DISCRECORD / sb->s_blocksize); 384 if (!bh) { 385 adfs_error(sb, "couldn't read superblock on " 386 "2nd try."); 387 goto error; 388 } 389 b_data = bh->b_data + (ADFS_DISCRECORD % sb->s_blocksize); 390 if (adfs_checkbblk(b_data)) { 391 adfs_error(sb, "disc record mismatch, very weird!"); 392 goto error_free_bh; 393 } 394 dr = (struct adfs_discrecord *)(b_data + ADFS_DR_OFFSET); 395 } else { 396 if (!silent) 397 printk(KERN_ERR "VFS: Unsupported blocksize on dev " 398 "%s.\n", sb->s_id); 399 goto error; 400 } 401 402 /* 403 * blocksize on this device should now be set to the ADFS log2secsize 404 */ 405 406 sb->s_magic = ADFS_SUPER_MAGIC; 407 asb->s_idlen = dr->idlen; 408 asb->s_map_size = dr->nzones | (dr->nzones_high << 8); 409 asb->s_map2blk = dr->log2bpmb - dr->log2secsize; 410 asb->s_size = adfs_discsize(dr, sb->s_blocksize_bits); 411 asb->s_version = dr->format_version; 412 asb->s_log2sharesize = dr->log2sharesize; 413 414 asb->s_map = adfs_read_map(sb, dr); 415 if (!asb->s_map) 416 goto error_free_bh; 417 418 brelse(bh); 419 420 /* 421 * set up enough so that we can read an inode 422 */ 423 sb->s_op = &adfs_sops; 424 425 dr = (struct adfs_discrecord *)(asb->s_map[0].dm_bh->b_data + 4); 426 427 root_obj.parent_id = root_obj.file_id = le32_to_cpu(dr->root); 428 root_obj.name_len = 0; 429 root_obj.loadaddr = 0; 430 root_obj.execaddr = 0; 431 root_obj.size = ADFS_NEWDIR_SIZE; 432 root_obj.attr = ADFS_NDA_DIRECTORY | ADFS_NDA_OWNER_READ | 433 ADFS_NDA_OWNER_WRITE | ADFS_NDA_PUBLIC_READ; 434 435 /* 436 * If this is a F+ disk with variable length directories, 437 * get the root_size from the disc record. 438 */ 439 if (asb->s_version) { 440 root_obj.size = le32_to_cpu(dr->root_size); 441 asb->s_dir = &adfs_fplus_dir_ops; 442 asb->s_namelen = ADFS_FPLUS_NAME_LEN; 443 } else { 444 asb->s_dir = &adfs_f_dir_ops; 445 asb->s_namelen = ADFS_F_NAME_LEN; 446 } 447 448 root = adfs_iget(sb, &root_obj); 449 sb->s_root = d_alloc_root(root); 450 if (!sb->s_root) { 451 int i; 452 iput(root); 453 for (i = 0; i < asb->s_map_size; i++) 454 brelse(asb->s_map[i].dm_bh); 455 kfree(asb->s_map); 456 adfs_error(sb, "get root inode failed\n"); 457 goto error; 458 } else 459 sb->s_root->d_op = &adfs_dentry_operations; 460 return 0; 461 462 error_free_bh: 463 brelse(bh); 464 error: 465 sb->s_fs_info = NULL; 466 kfree(asb); 467 return -EINVAL; 468 } 469 470 static int adfs_get_sb(struct file_system_type *fs_type, 471 int flags, const char *dev_name, void *data, struct vfsmount *mnt) 472 { 473 return get_sb_bdev(fs_type, flags, dev_name, data, adfs_fill_super, 474 mnt); 475 } 476 477 static struct file_system_type adfs_fs_type = { 478 .owner = THIS_MODULE, 479 .name = "adfs", 480 .get_sb = adfs_get_sb, 481 .kill_sb = kill_block_super, 482 .fs_flags = FS_REQUIRES_DEV, 483 }; 484 485 static int __init init_adfs_fs(void) 486 { 487 int err = init_inodecache(); 488 if (err) 489 goto out1; 490 err = register_filesystem(&adfs_fs_type); 491 if (err) 492 goto out; 493 return 0; 494 out: 495 destroy_inodecache(); 496 out1: 497 return err; 498 } 499 500 static void __exit exit_adfs_fs(void) 501 { 502 unregister_filesystem(&adfs_fs_type); 503 destroy_inodecache(); 504 } 505 506 module_init(init_adfs_fs) 507 module_exit(exit_adfs_fs) 508