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 = u64_to_fsid(id); 214 215 return 0; 216 } 217 218 static struct kmem_cache *adfs_inode_cachep; 219 220 static struct inode *adfs_alloc_inode(struct super_block *sb) 221 { 222 struct adfs_inode_info *ei; 223 ei = alloc_inode_sb(sb, adfs_inode_cachep, GFP_KERNEL); 224 if (!ei) 225 return NULL; 226 return &ei->vfs_inode; 227 } 228 229 static void adfs_free_inode(struct inode *inode) 230 { 231 kmem_cache_free(adfs_inode_cachep, ADFS_I(inode)); 232 } 233 234 static int adfs_drop_inode(struct inode *inode) 235 { 236 /* always drop inodes if we are read-only */ 237 return !IS_ENABLED(CONFIG_ADFS_FS_RW) || IS_RDONLY(inode); 238 } 239 240 static void init_once(void *foo) 241 { 242 struct adfs_inode_info *ei = (struct adfs_inode_info *) foo; 243 244 inode_init_once(&ei->vfs_inode); 245 } 246 247 static int __init init_inodecache(void) 248 { 249 adfs_inode_cachep = kmem_cache_create("adfs_inode_cache", 250 sizeof(struct adfs_inode_info), 251 0, (SLAB_RECLAIM_ACCOUNT| 252 SLAB_ACCOUNT), 253 init_once); 254 if (adfs_inode_cachep == NULL) 255 return -ENOMEM; 256 return 0; 257 } 258 259 static void destroy_inodecache(void) 260 { 261 /* 262 * Make sure all delayed rcu free inodes are flushed before we 263 * destroy cache. 264 */ 265 rcu_barrier(); 266 kmem_cache_destroy(adfs_inode_cachep); 267 } 268 269 static const struct super_operations adfs_sops = { 270 .alloc_inode = adfs_alloc_inode, 271 .free_inode = adfs_free_inode, 272 .drop_inode = adfs_drop_inode, 273 .write_inode = adfs_write_inode, 274 .put_super = adfs_put_super, 275 .statfs = adfs_statfs, 276 .remount_fs = adfs_remount, 277 .show_options = adfs_show_options, 278 }; 279 280 static int adfs_probe(struct super_block *sb, unsigned int offset, int silent, 281 int (*validate)(struct super_block *sb, 282 struct buffer_head *bh, 283 struct adfs_discrecord **bhp)) 284 { 285 struct adfs_sb_info *asb = ADFS_SB(sb); 286 struct adfs_discrecord *dr; 287 struct buffer_head *bh; 288 unsigned int blocksize = BLOCK_SIZE; 289 int ret, try; 290 291 for (try = 0; try < 2; try++) { 292 /* try to set the requested block size */ 293 if (sb->s_blocksize != blocksize && 294 !sb_set_blocksize(sb, blocksize)) { 295 if (!silent) 296 adfs_msg(sb, KERN_ERR, 297 "error: unsupported blocksize"); 298 return -EINVAL; 299 } 300 301 /* read the buffer */ 302 bh = sb_bread(sb, offset >> sb->s_blocksize_bits); 303 if (!bh) { 304 adfs_msg(sb, KERN_ERR, 305 "error: unable to read block %u, try %d", 306 offset >> sb->s_blocksize_bits, try); 307 return -EIO; 308 } 309 310 /* validate it */ 311 ret = validate(sb, bh, &dr); 312 if (ret) { 313 brelse(bh); 314 return ret; 315 } 316 317 /* does the block size match the filesystem block size? */ 318 blocksize = 1 << dr->log2secsize; 319 if (sb->s_blocksize == blocksize) { 320 asb->s_map = adfs_read_map(sb, dr); 321 brelse(bh); 322 return PTR_ERR_OR_ZERO(asb->s_map); 323 } 324 325 brelse(bh); 326 } 327 328 return -EIO; 329 } 330 331 static int adfs_validate_bblk(struct super_block *sb, struct buffer_head *bh, 332 struct adfs_discrecord **drp) 333 { 334 struct adfs_discrecord *dr; 335 unsigned char *b_data; 336 337 b_data = bh->b_data + (ADFS_DISCRECORD % sb->s_blocksize); 338 if (adfs_checkbblk(b_data)) 339 return -EILSEQ; 340 341 /* Do some sanity checks on the ADFS disc record */ 342 dr = (struct adfs_discrecord *)(b_data + ADFS_DR_OFFSET); 343 if (adfs_checkdiscrecord(dr)) 344 return -EILSEQ; 345 346 *drp = dr; 347 return 0; 348 } 349 350 static int adfs_validate_dr0(struct super_block *sb, struct buffer_head *bh, 351 struct adfs_discrecord **drp) 352 { 353 struct adfs_discrecord *dr; 354 355 /* Do some sanity checks on the ADFS disc record */ 356 dr = (struct adfs_discrecord *)(bh->b_data + 4); 357 if (adfs_checkdiscrecord(dr) || dr->nzones_high || dr->nzones != 1) 358 return -EILSEQ; 359 360 *drp = dr; 361 return 0; 362 } 363 364 static int adfs_fill_super(struct super_block *sb, void *data, int silent) 365 { 366 struct adfs_discrecord *dr; 367 struct object_info root_obj; 368 struct adfs_sb_info *asb; 369 struct inode *root; 370 int ret = -EINVAL; 371 372 sb->s_flags |= ADFS_SB_FLAGS; 373 374 asb = kzalloc(sizeof(*asb), GFP_KERNEL); 375 if (!asb) 376 return -ENOMEM; 377 378 sb->s_fs_info = asb; 379 sb->s_magic = ADFS_SUPER_MAGIC; 380 sb->s_time_gran = 10000000; 381 382 /* set default options */ 383 asb->s_uid = GLOBAL_ROOT_UID; 384 asb->s_gid = GLOBAL_ROOT_GID; 385 asb->s_owner_mask = ADFS_DEFAULT_OWNER_MASK; 386 asb->s_other_mask = ADFS_DEFAULT_OTHER_MASK; 387 asb->s_ftsuffix = 0; 388 389 if (parse_options(sb, asb, data)) 390 goto error; 391 392 /* Try to probe the filesystem boot block */ 393 ret = adfs_probe(sb, ADFS_DISCRECORD, 1, adfs_validate_bblk); 394 if (ret == -EILSEQ) 395 ret = adfs_probe(sb, 0, silent, adfs_validate_dr0); 396 if (ret == -EILSEQ) { 397 if (!silent) 398 adfs_msg(sb, KERN_ERR, 399 "error: can't find an ADFS filesystem on dev %s.", 400 sb->s_id); 401 ret = -EINVAL; 402 } 403 if (ret) 404 goto error; 405 406 /* set up enough so that we can read an inode */ 407 sb->s_op = &adfs_sops; 408 409 dr = adfs_map_discrecord(asb->s_map); 410 411 root_obj.parent_id = root_obj.indaddr = le32_to_cpu(dr->root); 412 root_obj.name_len = 0; 413 /* Set root object date as 01 Jan 1987 00:00:00 */ 414 root_obj.loadaddr = 0xfff0003f; 415 root_obj.execaddr = 0xec22c000; 416 root_obj.size = ADFS_NEWDIR_SIZE; 417 root_obj.attr = ADFS_NDA_DIRECTORY | ADFS_NDA_OWNER_READ | 418 ADFS_NDA_OWNER_WRITE | ADFS_NDA_PUBLIC_READ; 419 420 /* 421 * If this is a F+ disk with variable length directories, 422 * get the root_size from the disc record. 423 */ 424 if (dr->format_version) { 425 root_obj.size = le32_to_cpu(dr->root_size); 426 asb->s_dir = &adfs_fplus_dir_ops; 427 asb->s_namelen = ADFS_FPLUS_NAME_LEN; 428 } else { 429 asb->s_dir = &adfs_f_dir_ops; 430 asb->s_namelen = ADFS_F_NAME_LEN; 431 } 432 /* 433 * ,xyz hex filetype suffix may be added by driver 434 * to files that have valid RISC OS filetype 435 */ 436 if (asb->s_ftsuffix) 437 asb->s_namelen += 4; 438 439 sb->s_d_op = &adfs_dentry_operations; 440 root = adfs_iget(sb, &root_obj); 441 sb->s_root = d_make_root(root); 442 if (!sb->s_root) { 443 adfs_free_map(sb); 444 adfs_error(sb, "get root inode failed\n"); 445 ret = -EIO; 446 goto error; 447 } 448 return 0; 449 450 error: 451 sb->s_fs_info = NULL; 452 kfree(asb); 453 return ret; 454 } 455 456 static struct dentry *adfs_mount(struct file_system_type *fs_type, 457 int flags, const char *dev_name, void *data) 458 { 459 return mount_bdev(fs_type, flags, dev_name, data, adfs_fill_super); 460 } 461 462 static struct file_system_type adfs_fs_type = { 463 .owner = THIS_MODULE, 464 .name = "adfs", 465 .mount = adfs_mount, 466 .kill_sb = kill_block_super, 467 .fs_flags = FS_REQUIRES_DEV, 468 }; 469 MODULE_ALIAS_FS("adfs"); 470 471 static int __init init_adfs_fs(void) 472 { 473 int err = init_inodecache(); 474 if (err) 475 goto out1; 476 err = register_filesystem(&adfs_fs_type); 477 if (err) 478 goto out; 479 return 0; 480 out: 481 destroy_inodecache(); 482 out1: 483 return err; 484 } 485 486 static void __exit exit_adfs_fs(void) 487 { 488 unregister_filesystem(&adfs_fs_type); 489 destroy_inodecache(); 490 } 491 492 module_init(init_adfs_fs) 493 module_exit(exit_adfs_fs) 494 MODULE_DESCRIPTION("Acorn Disc Filing System"); 495 MODULE_LICENSE("GPL"); 496