1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * linux/fs/adfs/super.c 4 * 5 * Copyright (C) 1997-1999 Russell King 6 */ 7 #include <linux/module.h> 8 #include <linux/init.h> 9 #include <linux/parser.h> 10 #include <linux/mount.h> 11 #include <linux/seq_file.h> 12 #include <linux/slab.h> 13 #include <linux/statfs.h> 14 #include <linux/user_namespace.h> 15 #include <linux/blkdev.h> 16 #include "adfs.h" 17 #include "dir_f.h" 18 #include "dir_fplus.h" 19 20 #define ADFS_SB_FLAGS SB_NOATIME 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 struct va_format vaf; 28 va_list args; 29 30 va_start(args, fmt); 31 vaf.fmt = fmt; 32 vaf.va = &args; 33 34 printk(KERN_CRIT "ADFS-fs error (device %s)%s%s: %pV\n", 35 sb->s_id, function ? ": " : "", 36 function ? function : "", &vaf); 37 38 va_end(args); 39 } 40 41 void adfs_msg(struct super_block *sb, const char *pfx, const char *fmt, ...) 42 { 43 struct va_format vaf; 44 va_list args; 45 46 va_start(args, fmt); 47 vaf.fmt = fmt; 48 vaf.va = &args; 49 printk("%sADFS-fs (%s): %pV\n", pfx, sb->s_id, &vaf); 50 va_end(args); 51 } 52 53 static int adfs_checkdiscrecord(struct adfs_discrecord *dr) 54 { 55 unsigned int max_idlen; 56 int i; 57 58 /* sector size must be 256, 512 or 1024 bytes */ 59 if (dr->log2secsize != 8 && 60 dr->log2secsize != 9 && 61 dr->log2secsize != 10) 62 return 1; 63 64 /* idlen must be at least log2secsize + 3 */ 65 if (dr->idlen < dr->log2secsize + 3) 66 return 1; 67 68 /* we cannot have such a large disc that we 69 * are unable to represent sector offsets in 70 * 32 bits. This works out at 2.0 TB. 71 */ 72 if (le32_to_cpu(dr->disc_size_high) >> dr->log2secsize) 73 return 1; 74 75 /* 76 * Maximum idlen is limited to 16 bits for new directories by 77 * the three-byte storage of an indirect disc address. For 78 * big directories, idlen must be no greater than 19 v2 [1.0] 79 */ 80 max_idlen = dr->format_version ? 19 : 16; 81 if (dr->idlen > max_idlen) 82 return 1; 83 84 /* reserved bytes should be zero */ 85 for (i = 0; i < sizeof(dr->unused52); i++) 86 if (dr->unused52[i] != 0) 87 return 1; 88 89 return 0; 90 } 91 92 static void adfs_put_super(struct super_block *sb) 93 { 94 struct adfs_sb_info *asb = ADFS_SB(sb); 95 96 adfs_free_map(sb); 97 kfree_rcu(asb, rcu); 98 } 99 100 static int adfs_show_options(struct seq_file *seq, struct dentry *root) 101 { 102 struct adfs_sb_info *asb = ADFS_SB(root->d_sb); 103 104 if (!uid_eq(asb->s_uid, GLOBAL_ROOT_UID)) 105 seq_printf(seq, ",uid=%u", from_kuid_munged(&init_user_ns, asb->s_uid)); 106 if (!gid_eq(asb->s_gid, GLOBAL_ROOT_GID)) 107 seq_printf(seq, ",gid=%u", from_kgid_munged(&init_user_ns, asb->s_gid)); 108 if (asb->s_owner_mask != ADFS_DEFAULT_OWNER_MASK) 109 seq_printf(seq, ",ownmask=%o", asb->s_owner_mask); 110 if (asb->s_other_mask != ADFS_DEFAULT_OTHER_MASK) 111 seq_printf(seq, ",othmask=%o", asb->s_other_mask); 112 if (asb->s_ftsuffix != 0) 113 seq_printf(seq, ",ftsuffix=%u", asb->s_ftsuffix); 114 115 return 0; 116 } 117 118 enum {Opt_uid, Opt_gid, Opt_ownmask, Opt_othmask, Opt_ftsuffix, Opt_err}; 119 120 static const match_table_t tokens = { 121 {Opt_uid, "uid=%u"}, 122 {Opt_gid, "gid=%u"}, 123 {Opt_ownmask, "ownmask=%o"}, 124 {Opt_othmask, "othmask=%o"}, 125 {Opt_ftsuffix, "ftsuffix=%u"}, 126 {Opt_err, NULL} 127 }; 128 129 static int parse_options(struct super_block *sb, struct adfs_sb_info *asb, 130 char *options) 131 { 132 char *p; 133 int option; 134 135 if (!options) 136 return 0; 137 138 while ((p = strsep(&options, ",")) != NULL) { 139 substring_t args[MAX_OPT_ARGS]; 140 int token; 141 if (!*p) 142 continue; 143 144 token = match_token(p, tokens, args); 145 switch (token) { 146 case Opt_uid: 147 if (match_int(args, &option)) 148 return -EINVAL; 149 asb->s_uid = make_kuid(current_user_ns(), option); 150 if (!uid_valid(asb->s_uid)) 151 return -EINVAL; 152 break; 153 case Opt_gid: 154 if (match_int(args, &option)) 155 return -EINVAL; 156 asb->s_gid = make_kgid(current_user_ns(), option); 157 if (!gid_valid(asb->s_gid)) 158 return -EINVAL; 159 break; 160 case Opt_ownmask: 161 if (match_octal(args, &option)) 162 return -EINVAL; 163 asb->s_owner_mask = option; 164 break; 165 case Opt_othmask: 166 if (match_octal(args, &option)) 167 return -EINVAL; 168 asb->s_other_mask = option; 169 break; 170 case Opt_ftsuffix: 171 if (match_int(args, &option)) 172 return -EINVAL; 173 asb->s_ftsuffix = option; 174 break; 175 default: 176 adfs_msg(sb, KERN_ERR, 177 "unrecognised mount option \"%s\" or missing value", 178 p); 179 return -EINVAL; 180 } 181 } 182 return 0; 183 } 184 185 static int adfs_remount(struct super_block *sb, int *flags, char *data) 186 { 187 struct adfs_sb_info temp_asb; 188 int ret; 189 190 sync_filesystem(sb); 191 *flags |= ADFS_SB_FLAGS; 192 193 temp_asb = *ADFS_SB(sb); 194 ret = parse_options(sb, &temp_asb, data); 195 if (ret == 0) 196 *ADFS_SB(sb) = temp_asb; 197 198 return ret; 199 } 200 201 static int adfs_statfs(struct dentry *dentry, struct kstatfs *buf) 202 { 203 struct super_block *sb = dentry->d_sb; 204 struct adfs_sb_info *sbi = ADFS_SB(sb); 205 u64 id = huge_encode_dev(sb->s_bdev->bd_dev); 206 207 adfs_map_statfs(sb, buf); 208 209 buf->f_type = ADFS_SUPER_MAGIC; 210 buf->f_namelen = sbi->s_namelen; 211 buf->f_bsize = sb->s_blocksize; 212 buf->f_ffree = (long)(buf->f_bfree * buf->f_files) / (long)buf->f_blocks; 213 buf->f_fsid.val[0] = (u32)id; 214 buf->f_fsid.val[1] = (u32)(id >> 32); 215 216 return 0; 217 } 218 219 static struct kmem_cache *adfs_inode_cachep; 220 221 static struct inode *adfs_alloc_inode(struct super_block *sb) 222 { 223 struct adfs_inode_info *ei; 224 ei = kmem_cache_alloc(adfs_inode_cachep, GFP_KERNEL); 225 if (!ei) 226 return NULL; 227 return &ei->vfs_inode; 228 } 229 230 static void adfs_free_inode(struct inode *inode) 231 { 232 kmem_cache_free(adfs_inode_cachep, ADFS_I(inode)); 233 } 234 235 static int adfs_drop_inode(struct inode *inode) 236 { 237 /* always drop inodes if we are read-only */ 238 return !IS_ENABLED(CONFIG_ADFS_FS_RW) || IS_RDONLY(inode); 239 } 240 241 static void init_once(void *foo) 242 { 243 struct adfs_inode_info *ei = (struct adfs_inode_info *) foo; 244 245 inode_init_once(&ei->vfs_inode); 246 } 247 248 static int __init init_inodecache(void) 249 { 250 adfs_inode_cachep = kmem_cache_create("adfs_inode_cache", 251 sizeof(struct adfs_inode_info), 252 0, (SLAB_RECLAIM_ACCOUNT| 253 SLAB_MEM_SPREAD|SLAB_ACCOUNT), 254 init_once); 255 if (adfs_inode_cachep == NULL) 256 return -ENOMEM; 257 return 0; 258 } 259 260 static void destroy_inodecache(void) 261 { 262 /* 263 * Make sure all delayed rcu free inodes are flushed before we 264 * destroy cache. 265 */ 266 rcu_barrier(); 267 kmem_cache_destroy(adfs_inode_cachep); 268 } 269 270 static const struct super_operations adfs_sops = { 271 .alloc_inode = adfs_alloc_inode, 272 .free_inode = adfs_free_inode, 273 .drop_inode = adfs_drop_inode, 274 .write_inode = adfs_write_inode, 275 .put_super = adfs_put_super, 276 .statfs = adfs_statfs, 277 .remount_fs = adfs_remount, 278 .show_options = adfs_show_options, 279 }; 280 281 static int adfs_probe(struct super_block *sb, unsigned int offset, int silent, 282 int (*validate)(struct super_block *sb, 283 struct buffer_head *bh, 284 struct adfs_discrecord **bhp)) 285 { 286 struct adfs_sb_info *asb = ADFS_SB(sb); 287 struct adfs_discrecord *dr; 288 struct buffer_head *bh; 289 unsigned int blocksize = BLOCK_SIZE; 290 int ret, try; 291 292 for (try = 0; try < 2; try++) { 293 /* try to set the requested block size */ 294 if (sb->s_blocksize != blocksize && 295 !sb_set_blocksize(sb, blocksize)) { 296 if (!silent) 297 adfs_msg(sb, KERN_ERR, 298 "error: unsupported blocksize"); 299 return -EINVAL; 300 } 301 302 /* read the buffer */ 303 bh = sb_bread(sb, offset >> sb->s_blocksize_bits); 304 if (!bh) { 305 adfs_msg(sb, KERN_ERR, 306 "error: unable to read block %u, try %d", 307 offset >> sb->s_blocksize_bits, try); 308 return -EIO; 309 } 310 311 /* validate it */ 312 ret = validate(sb, bh, &dr); 313 if (ret) { 314 brelse(bh); 315 return ret; 316 } 317 318 /* does the block size match the filesystem block size? */ 319 blocksize = 1 << dr->log2secsize; 320 if (sb->s_blocksize == blocksize) { 321 asb->s_map = adfs_read_map(sb, dr); 322 brelse(bh); 323 return PTR_ERR_OR_ZERO(asb->s_map); 324 } 325 326 brelse(bh); 327 } 328 329 return -EIO; 330 } 331 332 static int adfs_validate_bblk(struct super_block *sb, struct buffer_head *bh, 333 struct adfs_discrecord **drp) 334 { 335 struct adfs_discrecord *dr; 336 unsigned char *b_data; 337 338 b_data = bh->b_data + (ADFS_DISCRECORD % sb->s_blocksize); 339 if (adfs_checkbblk(b_data)) 340 return -EILSEQ; 341 342 /* Do some sanity checks on the ADFS disc record */ 343 dr = (struct adfs_discrecord *)(b_data + ADFS_DR_OFFSET); 344 if (adfs_checkdiscrecord(dr)) 345 return -EILSEQ; 346 347 *drp = dr; 348 return 0; 349 } 350 351 static int adfs_validate_dr0(struct super_block *sb, struct buffer_head *bh, 352 struct adfs_discrecord **drp) 353 { 354 struct adfs_discrecord *dr; 355 356 /* Do some sanity checks on the ADFS disc record */ 357 dr = (struct adfs_discrecord *)(bh->b_data + 4); 358 if (adfs_checkdiscrecord(dr) || dr->nzones_high || dr->nzones != 1) 359 return -EILSEQ; 360 361 *drp = dr; 362 return 0; 363 } 364 365 static int adfs_fill_super(struct super_block *sb, void *data, int silent) 366 { 367 struct adfs_discrecord *dr; 368 struct object_info root_obj; 369 struct adfs_sb_info *asb; 370 struct inode *root; 371 int ret = -EINVAL; 372 373 sb->s_flags |= ADFS_SB_FLAGS; 374 375 asb = kzalloc(sizeof(*asb), GFP_KERNEL); 376 if (!asb) 377 return -ENOMEM; 378 379 sb->s_fs_info = asb; 380 sb->s_magic = ADFS_SUPER_MAGIC; 381 sb->s_time_gran = 10000000; 382 383 /* set default options */ 384 asb->s_uid = GLOBAL_ROOT_UID; 385 asb->s_gid = GLOBAL_ROOT_GID; 386 asb->s_owner_mask = ADFS_DEFAULT_OWNER_MASK; 387 asb->s_other_mask = ADFS_DEFAULT_OTHER_MASK; 388 asb->s_ftsuffix = 0; 389 390 if (parse_options(sb, asb, data)) 391 goto error; 392 393 /* Try to probe the filesystem boot block */ 394 ret = adfs_probe(sb, ADFS_DISCRECORD, 1, adfs_validate_bblk); 395 if (ret == -EILSEQ) 396 ret = adfs_probe(sb, 0, silent, adfs_validate_dr0); 397 if (ret == -EILSEQ) { 398 if (!silent) 399 adfs_msg(sb, KERN_ERR, 400 "error: can't find an ADFS filesystem on dev %s.", 401 sb->s_id); 402 ret = -EINVAL; 403 } 404 if (ret) 405 goto error; 406 407 /* set up enough so that we can read an inode */ 408 sb->s_op = &adfs_sops; 409 410 dr = adfs_map_discrecord(asb->s_map); 411 412 root_obj.parent_id = root_obj.indaddr = le32_to_cpu(dr->root); 413 root_obj.name_len = 0; 414 /* Set root object date as 01 Jan 1987 00:00:00 */ 415 root_obj.loadaddr = 0xfff0003f; 416 root_obj.execaddr = 0xec22c000; 417 root_obj.size = ADFS_NEWDIR_SIZE; 418 root_obj.attr = ADFS_NDA_DIRECTORY | ADFS_NDA_OWNER_READ | 419 ADFS_NDA_OWNER_WRITE | ADFS_NDA_PUBLIC_READ; 420 421 /* 422 * If this is a F+ disk with variable length directories, 423 * get the root_size from the disc record. 424 */ 425 if (dr->format_version) { 426 root_obj.size = le32_to_cpu(dr->root_size); 427 asb->s_dir = &adfs_fplus_dir_ops; 428 asb->s_namelen = ADFS_FPLUS_NAME_LEN; 429 } else { 430 asb->s_dir = &adfs_f_dir_ops; 431 asb->s_namelen = ADFS_F_NAME_LEN; 432 } 433 /* 434 * ,xyz hex filetype suffix may be added by driver 435 * to files that have valid RISC OS filetype 436 */ 437 if (asb->s_ftsuffix) 438 asb->s_namelen += 4; 439 440 sb->s_d_op = &adfs_dentry_operations; 441 root = adfs_iget(sb, &root_obj); 442 sb->s_root = d_make_root(root); 443 if (!sb->s_root) { 444 adfs_free_map(sb); 445 adfs_error(sb, "get root inode failed\n"); 446 ret = -EIO; 447 goto error; 448 } 449 return 0; 450 451 error: 452 sb->s_fs_info = NULL; 453 kfree(asb); 454 return ret; 455 } 456 457 static struct dentry *adfs_mount(struct file_system_type *fs_type, 458 int flags, const char *dev_name, void *data) 459 { 460 return mount_bdev(fs_type, flags, dev_name, data, adfs_fill_super); 461 } 462 463 static struct file_system_type adfs_fs_type = { 464 .owner = THIS_MODULE, 465 .name = "adfs", 466 .mount = adfs_mount, 467 .kill_sb = kill_block_super, 468 .fs_flags = FS_REQUIRES_DEV, 469 }; 470 MODULE_ALIAS_FS("adfs"); 471 472 static int __init init_adfs_fs(void) 473 { 474 int err = init_inodecache(); 475 if (err) 476 goto out1; 477 err = register_filesystem(&adfs_fs_type); 478 if (err) 479 goto out; 480 return 0; 481 out: 482 destroy_inodecache(); 483 out1: 484 return err; 485 } 486 487 static void __exit exit_adfs_fs(void) 488 { 489 unregister_filesystem(&adfs_fs_type); 490 destroy_inodecache(); 491 } 492 493 module_init(init_adfs_fs) 494 module_exit(exit_adfs_fs) 495 MODULE_LICENSE("GPL"); 496