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/fs_parser.h> 10 #include <linux/fs_context.h> 11 #include <linux/mount.h> 12 #include <linux/seq_file.h> 13 #include <linux/slab.h> 14 #include <linux/statfs.h> 15 #include <linux/user_namespace.h> 16 #include <linux/blkdev.h> 17 #include "adfs.h" 18 #include "dir_f.h" 19 #include "dir_fplus.h" 20 21 #define ADFS_SB_FLAGS SB_NOATIME 22 23 #define ADFS_DEFAULT_OWNER_MASK S_IRWXU 24 #define ADFS_DEFAULT_OTHER_MASK (S_IRWXG | S_IRWXO) 25 26 void __adfs_error(struct super_block *sb, const char *function, const char *fmt, ...) 27 { 28 struct va_format vaf; 29 va_list args; 30 31 va_start(args, fmt); 32 vaf.fmt = fmt; 33 vaf.va = &args; 34 35 printk(KERN_CRIT "ADFS-fs error (device %s)%s%s: %pV\n", 36 sb->s_id, function ? ": " : "", 37 function ? function : "", &vaf); 38 39 va_end(args); 40 } 41 42 void adfs_msg(struct super_block *sb, const char *pfx, const char *fmt, ...) 43 { 44 struct va_format vaf; 45 va_list args; 46 47 va_start(args, fmt); 48 vaf.fmt = fmt; 49 vaf.va = &args; 50 printk("%sADFS-fs (%s): %pV\n", pfx, sb->s_id, &vaf); 51 va_end(args); 52 } 53 54 static int adfs_checkdiscrecord(struct adfs_discrecord *dr) 55 { 56 unsigned int max_idlen; 57 int i; 58 59 /* sector size must be 256, 512 or 1024 bytes */ 60 if (dr->log2secsize != 8 && 61 dr->log2secsize != 9 && 62 dr->log2secsize != 10) 63 return 1; 64 65 /* idlen must be at least log2secsize + 3 */ 66 if (dr->idlen < dr->log2secsize + 3) 67 return 1; 68 69 /* we cannot have such a large disc that we 70 * are unable to represent sector offsets in 71 * 32 bits. This works out at 2.0 TB. 72 */ 73 if (le32_to_cpu(dr->disc_size_high) >> dr->log2secsize) 74 return 1; 75 76 /* 77 * Maximum idlen is limited to 16 bits for new directories by 78 * the three-byte storage of an indirect disc address. For 79 * big directories, idlen must be no greater than 19 v2 [1.0] 80 */ 81 max_idlen = dr->format_version ? 19 : 16; 82 if (dr->idlen > max_idlen) 83 return 1; 84 85 /* reserved bytes should be zero */ 86 for (i = 0; i < sizeof(dr->unused52); i++) 87 if (dr->unused52[i] != 0) 88 return 1; 89 90 return 0; 91 } 92 93 static void adfs_put_super(struct super_block *sb) 94 { 95 struct adfs_sb_info *asb = ADFS_SB(sb); 96 97 adfs_free_map(sb); 98 kfree_rcu(asb, rcu); 99 } 100 101 static int adfs_show_options(struct seq_file *seq, struct dentry *root) 102 { 103 struct adfs_sb_info *asb = ADFS_SB(root->d_sb); 104 105 if (!uid_eq(asb->s_uid, GLOBAL_ROOT_UID)) 106 seq_printf(seq, ",uid=%u", from_kuid_munged(&init_user_ns, asb->s_uid)); 107 if (!gid_eq(asb->s_gid, GLOBAL_ROOT_GID)) 108 seq_printf(seq, ",gid=%u", from_kgid_munged(&init_user_ns, asb->s_gid)); 109 if (asb->s_owner_mask != ADFS_DEFAULT_OWNER_MASK) 110 seq_printf(seq, ",ownmask=%o", asb->s_owner_mask); 111 if (asb->s_other_mask != ADFS_DEFAULT_OTHER_MASK) 112 seq_printf(seq, ",othmask=%o", asb->s_other_mask); 113 if (asb->s_ftsuffix != 0) 114 seq_printf(seq, ",ftsuffix=%u", asb->s_ftsuffix); 115 116 return 0; 117 } 118 119 enum {Opt_uid, Opt_gid, Opt_ownmask, Opt_othmask, Opt_ftsuffix}; 120 121 static const struct fs_parameter_spec adfs_param_spec[] = { 122 fsparam_uid ("uid", Opt_uid), 123 fsparam_gid ("gid", Opt_gid), 124 fsparam_u32oct ("ownmask", Opt_ownmask), 125 fsparam_u32oct ("othmask", Opt_othmask), 126 fsparam_u32 ("ftsuffix", Opt_ftsuffix), 127 {} 128 }; 129 130 static int adfs_parse_param(struct fs_context *fc, struct fs_parameter *param) 131 { 132 struct adfs_sb_info *asb = fc->s_fs_info; 133 struct fs_parse_result result; 134 int opt; 135 136 opt = fs_parse(fc, adfs_param_spec, param, &result); 137 if (opt < 0) 138 return opt; 139 140 switch (opt) { 141 case Opt_uid: 142 asb->s_uid = result.uid; 143 break; 144 case Opt_gid: 145 asb->s_gid = result.gid; 146 break; 147 case Opt_ownmask: 148 asb->s_owner_mask = result.uint_32; 149 break; 150 case Opt_othmask: 151 asb->s_other_mask = result.uint_32; 152 break; 153 case Opt_ftsuffix: 154 asb->s_ftsuffix = result.uint_32; 155 break; 156 default: 157 return -EINVAL; 158 } 159 return 0; 160 } 161 162 static int adfs_reconfigure(struct fs_context *fc) 163 { 164 struct adfs_sb_info *new_asb = fc->s_fs_info; 165 struct adfs_sb_info *asb = ADFS_SB(fc->root->d_sb); 166 167 sync_filesystem(fc->root->d_sb); 168 fc->sb_flags |= ADFS_SB_FLAGS; 169 170 /* Structure copy newly parsed options */ 171 *asb = *new_asb; 172 173 return 0; 174 } 175 176 static int adfs_statfs(struct dentry *dentry, struct kstatfs *buf) 177 { 178 struct super_block *sb = dentry->d_sb; 179 struct adfs_sb_info *sbi = ADFS_SB(sb); 180 u64 id = huge_encode_dev(sb->s_bdev->bd_dev); 181 182 adfs_map_statfs(sb, buf); 183 184 buf->f_type = ADFS_SUPER_MAGIC; 185 buf->f_namelen = sbi->s_namelen; 186 buf->f_bsize = sb->s_blocksize; 187 buf->f_ffree = (long)(buf->f_bfree * buf->f_files) / (long)buf->f_blocks; 188 buf->f_fsid = u64_to_fsid(id); 189 190 return 0; 191 } 192 193 static struct kmem_cache *adfs_inode_cachep; 194 195 static struct inode *adfs_alloc_inode(struct super_block *sb) 196 { 197 struct adfs_inode_info *ei; 198 ei = alloc_inode_sb(sb, adfs_inode_cachep, GFP_KERNEL); 199 if (!ei) 200 return NULL; 201 return &ei->vfs_inode; 202 } 203 204 static void adfs_free_inode(struct inode *inode) 205 { 206 kmem_cache_free(adfs_inode_cachep, ADFS_I(inode)); 207 } 208 209 static int adfs_drop_inode(struct inode *inode) 210 { 211 /* always drop inodes if we are read-only */ 212 return !IS_ENABLED(CONFIG_ADFS_FS_RW) || IS_RDONLY(inode); 213 } 214 215 static void init_once(void *foo) 216 { 217 struct adfs_inode_info *ei = (struct adfs_inode_info *) foo; 218 219 inode_init_once(&ei->vfs_inode); 220 } 221 222 static int __init init_inodecache(void) 223 { 224 adfs_inode_cachep = kmem_cache_create("adfs_inode_cache", 225 sizeof(struct adfs_inode_info), 226 0, (SLAB_RECLAIM_ACCOUNT| 227 SLAB_ACCOUNT), 228 init_once); 229 if (adfs_inode_cachep == NULL) 230 return -ENOMEM; 231 return 0; 232 } 233 234 static void destroy_inodecache(void) 235 { 236 /* 237 * Make sure all delayed rcu free inodes are flushed before we 238 * destroy cache. 239 */ 240 rcu_barrier(); 241 kmem_cache_destroy(adfs_inode_cachep); 242 } 243 244 static const struct super_operations adfs_sops = { 245 .alloc_inode = adfs_alloc_inode, 246 .free_inode = adfs_free_inode, 247 .drop_inode = adfs_drop_inode, 248 .write_inode = adfs_write_inode, 249 .put_super = adfs_put_super, 250 .statfs = adfs_statfs, 251 .show_options = adfs_show_options, 252 }; 253 254 static int adfs_probe(struct super_block *sb, unsigned int offset, int silent, 255 int (*validate)(struct super_block *sb, 256 struct buffer_head *bh, 257 struct adfs_discrecord **bhp)) 258 { 259 struct adfs_sb_info *asb = ADFS_SB(sb); 260 struct adfs_discrecord *dr; 261 struct buffer_head *bh; 262 unsigned int blocksize = BLOCK_SIZE; 263 int ret, try; 264 265 for (try = 0; try < 2; try++) { 266 /* try to set the requested block size */ 267 if (sb->s_blocksize != blocksize && 268 !sb_set_blocksize(sb, blocksize)) { 269 if (!silent) 270 adfs_msg(sb, KERN_ERR, 271 "error: unsupported blocksize"); 272 return -EINVAL; 273 } 274 275 /* read the buffer */ 276 bh = sb_bread(sb, offset >> sb->s_blocksize_bits); 277 if (!bh) { 278 adfs_msg(sb, KERN_ERR, 279 "error: unable to read block %u, try %d", 280 offset >> sb->s_blocksize_bits, try); 281 return -EIO; 282 } 283 284 /* validate it */ 285 ret = validate(sb, bh, &dr); 286 if (ret) { 287 brelse(bh); 288 return ret; 289 } 290 291 /* does the block size match the filesystem block size? */ 292 blocksize = 1 << dr->log2secsize; 293 if (sb->s_blocksize == blocksize) { 294 asb->s_map = adfs_read_map(sb, dr); 295 brelse(bh); 296 return PTR_ERR_OR_ZERO(asb->s_map); 297 } 298 299 brelse(bh); 300 } 301 302 return -EIO; 303 } 304 305 static int adfs_validate_bblk(struct super_block *sb, struct buffer_head *bh, 306 struct adfs_discrecord **drp) 307 { 308 struct adfs_discrecord *dr; 309 unsigned char *b_data; 310 311 b_data = bh->b_data + (ADFS_DISCRECORD % sb->s_blocksize); 312 if (adfs_checkbblk(b_data)) 313 return -EILSEQ; 314 315 /* Do some sanity checks on the ADFS disc record */ 316 dr = (struct adfs_discrecord *)(b_data + ADFS_DR_OFFSET); 317 if (adfs_checkdiscrecord(dr)) 318 return -EILSEQ; 319 320 *drp = dr; 321 return 0; 322 } 323 324 static int adfs_validate_dr0(struct super_block *sb, struct buffer_head *bh, 325 struct adfs_discrecord **drp) 326 { 327 struct adfs_discrecord *dr; 328 329 /* Do some sanity checks on the ADFS disc record */ 330 dr = (struct adfs_discrecord *)(bh->b_data + 4); 331 if (adfs_checkdiscrecord(dr) || dr->nzones_high || dr->nzones != 1) 332 return -EILSEQ; 333 334 *drp = dr; 335 return 0; 336 } 337 338 static int adfs_fill_super(struct super_block *sb, struct fs_context *fc) 339 { 340 struct adfs_discrecord *dr; 341 struct object_info root_obj; 342 struct adfs_sb_info *asb = sb->s_fs_info; 343 struct inode *root; 344 int ret = -EINVAL; 345 int silent = fc->sb_flags & SB_SILENT; 346 347 sb->s_flags |= ADFS_SB_FLAGS; 348 349 sb->s_fs_info = asb; 350 sb->s_magic = ADFS_SUPER_MAGIC; 351 sb->s_time_gran = 10000000; 352 353 /* Try to probe the filesystem boot block */ 354 ret = adfs_probe(sb, ADFS_DISCRECORD, 1, adfs_validate_bblk); 355 if (ret == -EILSEQ) 356 ret = adfs_probe(sb, 0, silent, adfs_validate_dr0); 357 if (ret == -EILSEQ) { 358 if (!silent) 359 adfs_msg(sb, KERN_ERR, 360 "error: can't find an ADFS filesystem on dev %s.", 361 sb->s_id); 362 ret = -EINVAL; 363 } 364 if (ret) 365 goto error; 366 367 /* set up enough so that we can read an inode */ 368 sb->s_op = &adfs_sops; 369 370 dr = adfs_map_discrecord(asb->s_map); 371 372 root_obj.parent_id = root_obj.indaddr = le32_to_cpu(dr->root); 373 root_obj.name_len = 0; 374 /* Set root object date as 01 Jan 1987 00:00:00 */ 375 root_obj.loadaddr = 0xfff0003f; 376 root_obj.execaddr = 0xec22c000; 377 root_obj.size = ADFS_NEWDIR_SIZE; 378 root_obj.attr = ADFS_NDA_DIRECTORY | ADFS_NDA_OWNER_READ | 379 ADFS_NDA_OWNER_WRITE | ADFS_NDA_PUBLIC_READ; 380 381 /* 382 * If this is a F+ disk with variable length directories, 383 * get the root_size from the disc record. 384 */ 385 if (dr->format_version) { 386 root_obj.size = le32_to_cpu(dr->root_size); 387 asb->s_dir = &adfs_fplus_dir_ops; 388 asb->s_namelen = ADFS_FPLUS_NAME_LEN; 389 } else { 390 asb->s_dir = &adfs_f_dir_ops; 391 asb->s_namelen = ADFS_F_NAME_LEN; 392 } 393 /* 394 * ,xyz hex filetype suffix may be added by driver 395 * to files that have valid RISC OS filetype 396 */ 397 if (asb->s_ftsuffix) 398 asb->s_namelen += 4; 399 400 sb->s_d_op = &adfs_dentry_operations; 401 root = adfs_iget(sb, &root_obj); 402 sb->s_root = d_make_root(root); 403 if (!sb->s_root) { 404 adfs_free_map(sb); 405 adfs_error(sb, "get root inode failed\n"); 406 ret = -EIO; 407 goto error; 408 } 409 return 0; 410 411 error: 412 sb->s_fs_info = NULL; 413 kfree(asb); 414 return ret; 415 } 416 417 static int adfs_get_tree(struct fs_context *fc) 418 { 419 return get_tree_bdev(fc, adfs_fill_super); 420 } 421 422 static void adfs_free_fc(struct fs_context *fc) 423 { 424 struct adfs_context *asb = fc->s_fs_info; 425 426 kfree(asb); 427 } 428 429 static const struct fs_context_operations adfs_context_ops = { 430 .parse_param = adfs_parse_param, 431 .get_tree = adfs_get_tree, 432 .reconfigure = adfs_reconfigure, 433 .free = adfs_free_fc, 434 }; 435 436 static int adfs_init_fs_context(struct fs_context *fc) 437 { 438 struct adfs_sb_info *asb; 439 440 asb = kzalloc(sizeof(struct adfs_sb_info), GFP_KERNEL); 441 if (!asb) 442 return -ENOMEM; 443 444 if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE) { 445 struct super_block *sb = fc->root->d_sb; 446 struct adfs_sb_info *old_asb = ADFS_SB(sb); 447 448 /* structure copy existing options before parsing */ 449 *asb = *old_asb; 450 } else { 451 /* set default options */ 452 asb->s_uid = GLOBAL_ROOT_UID; 453 asb->s_gid = GLOBAL_ROOT_GID; 454 asb->s_owner_mask = ADFS_DEFAULT_OWNER_MASK; 455 asb->s_other_mask = ADFS_DEFAULT_OTHER_MASK; 456 asb->s_ftsuffix = 0; 457 } 458 459 fc->ops = &adfs_context_ops; 460 fc->s_fs_info = asb; 461 462 return 0; 463 } 464 465 static struct file_system_type adfs_fs_type = { 466 .owner = THIS_MODULE, 467 .name = "adfs", 468 .kill_sb = kill_block_super, 469 .fs_flags = FS_REQUIRES_DEV, 470 .init_fs_context = adfs_init_fs_context, 471 .parameters = adfs_param_spec, 472 }; 473 MODULE_ALIAS_FS("adfs"); 474 475 static int __init init_adfs_fs(void) 476 { 477 int err = init_inodecache(); 478 if (err) 479 goto out1; 480 err = register_filesystem(&adfs_fs_type); 481 if (err) 482 goto out; 483 return 0; 484 out: 485 destroy_inodecache(); 486 out1: 487 return err; 488 } 489 490 static void __exit exit_adfs_fs(void) 491 { 492 unregister_filesystem(&adfs_fs_type); 493 destroy_inodecache(); 494 } 495 496 module_init(init_adfs_fs) 497 module_exit(exit_adfs_fs) 498 MODULE_DESCRIPTION("Acorn Disc Filing System"); 499 MODULE_LICENSE("GPL"); 500