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 vsprintf(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 kmem_cache_t *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, SLAB_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, kmem_cache_t * cachep, unsigned long flags) 232 { 233 struct adfs_inode_info *ei = (struct adfs_inode_info *) foo; 234 235 if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) == 236 SLAB_CTOR_CONSTRUCTOR) 237 inode_init_once(&ei->vfs_inode); 238 } 239 240 static int init_inodecache(void) 241 { 242 adfs_inode_cachep = kmem_cache_create("adfs_inode_cache", 243 sizeof(struct adfs_inode_info), 244 0, (SLAB_RECLAIM_ACCOUNT| 245 SLAB_MEM_SPREAD), 246 init_once, NULL); 247 if (adfs_inode_cachep == NULL) 248 return -ENOMEM; 249 return 0; 250 } 251 252 static void destroy_inodecache(void) 253 { 254 kmem_cache_destroy(adfs_inode_cachep); 255 } 256 257 static struct super_operations adfs_sops = { 258 .alloc_inode = adfs_alloc_inode, 259 .destroy_inode = adfs_destroy_inode, 260 .write_inode = adfs_write_inode, 261 .put_super = adfs_put_super, 262 .statfs = adfs_statfs, 263 .remount_fs = adfs_remount, 264 }; 265 266 static struct adfs_discmap *adfs_read_map(struct super_block *sb, struct adfs_discrecord *dr) 267 { 268 struct adfs_discmap *dm; 269 unsigned int map_addr, zone_size, nzones; 270 int i, zone; 271 struct adfs_sb_info *asb = ADFS_SB(sb); 272 273 nzones = asb->s_map_size; 274 zone_size = (8 << dr->log2secsize) - le16_to_cpu(dr->zone_spare); 275 map_addr = (nzones >> 1) * zone_size - 276 ((nzones > 1) ? ADFS_DR_SIZE_BITS : 0); 277 map_addr = signed_asl(map_addr, asb->s_map2blk); 278 279 asb->s_ids_per_zone = zone_size / (asb->s_idlen + 1); 280 281 dm = kmalloc(nzones * sizeof(*dm), GFP_KERNEL); 282 if (dm == NULL) { 283 adfs_error(sb, "not enough memory"); 284 return NULL; 285 } 286 287 for (zone = 0; zone < nzones; zone++, map_addr++) { 288 dm[zone].dm_startbit = 0; 289 dm[zone].dm_endbit = zone_size; 290 dm[zone].dm_startblk = zone * zone_size - ADFS_DR_SIZE_BITS; 291 dm[zone].dm_bh = sb_bread(sb, map_addr); 292 293 if (!dm[zone].dm_bh) { 294 adfs_error(sb, "unable to read map"); 295 goto error_free; 296 } 297 } 298 299 /* adjust the limits for the first and last map zones */ 300 i = zone - 1; 301 dm[0].dm_startblk = 0; 302 dm[0].dm_startbit = ADFS_DR_SIZE_BITS; 303 dm[i].dm_endbit = (le32_to_cpu(dr->disc_size_high) << (32 - dr->log2bpmb)) + 304 (le32_to_cpu(dr->disc_size) >> dr->log2bpmb) + 305 (ADFS_DR_SIZE_BITS - i * zone_size); 306 307 if (adfs_checkmap(sb, dm)) 308 return dm; 309 310 adfs_error(sb, "map corrupted"); 311 312 error_free: 313 while (--zone >= 0) 314 brelse(dm[zone].dm_bh); 315 316 kfree(dm); 317 return NULL; 318 } 319 320 static inline unsigned long adfs_discsize(struct adfs_discrecord *dr, int block_bits) 321 { 322 unsigned long discsize; 323 324 discsize = le32_to_cpu(dr->disc_size_high) << (32 - block_bits); 325 discsize |= le32_to_cpu(dr->disc_size) >> block_bits; 326 327 return discsize; 328 } 329 330 static int adfs_fill_super(struct super_block *sb, void *data, int silent) 331 { 332 struct adfs_discrecord *dr; 333 struct buffer_head *bh; 334 struct object_info root_obj; 335 unsigned char *b_data; 336 struct adfs_sb_info *asb; 337 struct inode *root; 338 339 sb->s_flags |= MS_NODIRATIME; 340 341 asb = kzalloc(sizeof(*asb), GFP_KERNEL); 342 if (!asb) 343 return -ENOMEM; 344 sb->s_fs_info = asb; 345 346 /* set default options */ 347 asb->s_uid = 0; 348 asb->s_gid = 0; 349 asb->s_owner_mask = S_IRWXU; 350 asb->s_other_mask = S_IRWXG | S_IRWXO; 351 352 if (parse_options(sb, data)) 353 goto error; 354 355 sb_set_blocksize(sb, BLOCK_SIZE); 356 if (!(bh = sb_bread(sb, ADFS_DISCRECORD / BLOCK_SIZE))) { 357 adfs_error(sb, "unable to read superblock"); 358 goto error; 359 } 360 361 b_data = bh->b_data + (ADFS_DISCRECORD % BLOCK_SIZE); 362 363 if (adfs_checkbblk(b_data)) { 364 if (!silent) 365 printk("VFS: Can't find an adfs filesystem on dev " 366 "%s.\n", sb->s_id); 367 goto error_free_bh; 368 } 369 370 dr = (struct adfs_discrecord *)(b_data + ADFS_DR_OFFSET); 371 372 /* 373 * Do some sanity checks on the ADFS disc record 374 */ 375 if (adfs_checkdiscrecord(dr)) { 376 if (!silent) 377 printk("VPS: Can't find an adfs filesystem on dev " 378 "%s.\n", sb->s_id); 379 goto error_free_bh; 380 } 381 382 brelse(bh); 383 if (sb_set_blocksize(sb, 1 << dr->log2secsize)) { 384 bh = sb_bread(sb, ADFS_DISCRECORD / sb->s_blocksize); 385 if (!bh) { 386 adfs_error(sb, "couldn't read superblock on " 387 "2nd try."); 388 goto error; 389 } 390 b_data = bh->b_data + (ADFS_DISCRECORD % sb->s_blocksize); 391 if (adfs_checkbblk(b_data)) { 392 adfs_error(sb, "disc record mismatch, very weird!"); 393 goto error_free_bh; 394 } 395 dr = (struct adfs_discrecord *)(b_data + ADFS_DR_OFFSET); 396 } else { 397 if (!silent) 398 printk(KERN_ERR "VFS: Unsupported blocksize on dev " 399 "%s.\n", sb->s_id); 400 goto error; 401 } 402 403 /* 404 * blocksize on this device should now be set to the ADFS log2secsize 405 */ 406 407 sb->s_magic = ADFS_SUPER_MAGIC; 408 asb->s_idlen = dr->idlen; 409 asb->s_map_size = dr->nzones | (dr->nzones_high << 8); 410 asb->s_map2blk = dr->log2bpmb - dr->log2secsize; 411 asb->s_size = adfs_discsize(dr, sb->s_blocksize_bits); 412 asb->s_version = dr->format_version; 413 asb->s_log2sharesize = dr->log2sharesize; 414 415 asb->s_map = adfs_read_map(sb, dr); 416 if (!asb->s_map) 417 goto error_free_bh; 418 419 brelse(bh); 420 421 /* 422 * set up enough so that we can read an inode 423 */ 424 sb->s_op = &adfs_sops; 425 426 dr = (struct adfs_discrecord *)(asb->s_map[0].dm_bh->b_data + 4); 427 428 root_obj.parent_id = root_obj.file_id = le32_to_cpu(dr->root); 429 root_obj.name_len = 0; 430 root_obj.loadaddr = 0; 431 root_obj.execaddr = 0; 432 root_obj.size = ADFS_NEWDIR_SIZE; 433 root_obj.attr = ADFS_NDA_DIRECTORY | ADFS_NDA_OWNER_READ | 434 ADFS_NDA_OWNER_WRITE | ADFS_NDA_PUBLIC_READ; 435 436 /* 437 * If this is a F+ disk with variable length directories, 438 * get the root_size from the disc record. 439 */ 440 if (asb->s_version) { 441 root_obj.size = le32_to_cpu(dr->root_size); 442 asb->s_dir = &adfs_fplus_dir_ops; 443 asb->s_namelen = ADFS_FPLUS_NAME_LEN; 444 } else { 445 asb->s_dir = &adfs_f_dir_ops; 446 asb->s_namelen = ADFS_F_NAME_LEN; 447 } 448 449 root = adfs_iget(sb, &root_obj); 450 sb->s_root = d_alloc_root(root); 451 if (!sb->s_root) { 452 int i; 453 iput(root); 454 for (i = 0; i < asb->s_map_size; i++) 455 brelse(asb->s_map[i].dm_bh); 456 kfree(asb->s_map); 457 adfs_error(sb, "get root inode failed\n"); 458 goto error; 459 } else 460 sb->s_root->d_op = &adfs_dentry_operations; 461 return 0; 462 463 error_free_bh: 464 brelse(bh); 465 error: 466 sb->s_fs_info = NULL; 467 kfree(asb); 468 return -EINVAL; 469 } 470 471 static int adfs_get_sb(struct file_system_type *fs_type, 472 int flags, const char *dev_name, void *data, struct vfsmount *mnt) 473 { 474 return get_sb_bdev(fs_type, flags, dev_name, data, adfs_fill_super, 475 mnt); 476 } 477 478 static struct file_system_type adfs_fs_type = { 479 .owner = THIS_MODULE, 480 .name = "adfs", 481 .get_sb = adfs_get_sb, 482 .kill_sb = kill_block_super, 483 .fs_flags = FS_REQUIRES_DEV, 484 }; 485 486 static int __init init_adfs_fs(void) 487 { 488 int err = init_inodecache(); 489 if (err) 490 goto out1; 491 err = register_filesystem(&adfs_fs_type); 492 if (err) 493 goto out; 494 return 0; 495 out: 496 destroy_inodecache(); 497 out1: 498 return err; 499 } 500 501 static void __exit exit_adfs_fs(void) 502 { 503 unregister_filesystem(&adfs_fs_type); 504 destroy_inodecache(); 505 } 506 507 module_init(init_adfs_fs) 508 module_exit(exit_adfs_fs) 509