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 adfs_free_map(sb); 96 } 97 98 static int adfs_show_options(struct seq_file *seq, struct dentry *root) 99 { 100 struct adfs_sb_info *asb = ADFS_SB(root->d_sb); 101 102 if (!uid_eq(asb->s_uid, GLOBAL_ROOT_UID)) 103 seq_printf(seq, ",uid=%u", from_kuid_munged(&init_user_ns, asb->s_uid)); 104 if (!gid_eq(asb->s_gid, GLOBAL_ROOT_GID)) 105 seq_printf(seq, ",gid=%u", from_kgid_munged(&init_user_ns, asb->s_gid)); 106 if (asb->s_owner_mask != ADFS_DEFAULT_OWNER_MASK) 107 seq_printf(seq, ",ownmask=%o", asb->s_owner_mask); 108 if (asb->s_other_mask != ADFS_DEFAULT_OTHER_MASK) 109 seq_printf(seq, ",othmask=%o", asb->s_other_mask); 110 if (asb->s_ftsuffix != 0) 111 seq_printf(seq, ",ftsuffix=%u", asb->s_ftsuffix); 112 113 return 0; 114 } 115 116 enum {Opt_uid, Opt_gid, Opt_ownmask, Opt_othmask, Opt_ftsuffix}; 117 118 static const struct fs_parameter_spec adfs_param_spec[] = { 119 fsparam_uid ("uid", Opt_uid), 120 fsparam_gid ("gid", Opt_gid), 121 fsparam_u32oct ("ownmask", Opt_ownmask), 122 fsparam_u32oct ("othmask", Opt_othmask), 123 fsparam_u32 ("ftsuffix", Opt_ftsuffix), 124 {} 125 }; 126 127 static int adfs_parse_param(struct fs_context *fc, struct fs_parameter *param) 128 { 129 struct adfs_sb_info *asb = fc->s_fs_info; 130 struct fs_parse_result result; 131 int opt; 132 133 opt = fs_parse(fc, adfs_param_spec, param, &result); 134 if (opt < 0) 135 return opt; 136 137 switch (opt) { 138 case Opt_uid: 139 asb->s_uid = result.uid; 140 break; 141 case Opt_gid: 142 asb->s_gid = result.gid; 143 break; 144 case Opt_ownmask: 145 asb->s_owner_mask = result.uint_32; 146 break; 147 case Opt_othmask: 148 asb->s_other_mask = result.uint_32; 149 break; 150 case Opt_ftsuffix: 151 asb->s_ftsuffix = result.uint_32; 152 break; 153 default: 154 return -EINVAL; 155 } 156 return 0; 157 } 158 159 static int adfs_reconfigure(struct fs_context *fc) 160 { 161 struct adfs_sb_info *new_asb = fc->s_fs_info; 162 struct adfs_sb_info *asb = ADFS_SB(fc->root->d_sb); 163 164 sync_filesystem(fc->root->d_sb); 165 fc->sb_flags |= ADFS_SB_FLAGS; 166 167 /* Structure copy newly parsed options */ 168 *asb = *new_asb; 169 170 return 0; 171 } 172 173 static int adfs_statfs(struct dentry *dentry, struct kstatfs *buf) 174 { 175 struct super_block *sb = dentry->d_sb; 176 struct adfs_sb_info *sbi = ADFS_SB(sb); 177 u64 id = huge_encode_dev(sb->s_bdev->bd_dev); 178 179 adfs_map_statfs(sb, buf); 180 181 buf->f_type = ADFS_SUPER_MAGIC; 182 buf->f_namelen = sbi->s_namelen; 183 buf->f_bsize = sb->s_blocksize; 184 buf->f_ffree = (long)(buf->f_bfree * buf->f_files) / (long)buf->f_blocks; 185 buf->f_fsid = u64_to_fsid(id); 186 187 return 0; 188 } 189 190 static struct kmem_cache *adfs_inode_cachep; 191 192 static struct inode *adfs_alloc_inode(struct super_block *sb) 193 { 194 struct adfs_inode_info *ei; 195 ei = alloc_inode_sb(sb, adfs_inode_cachep, GFP_KERNEL); 196 if (!ei) 197 return NULL; 198 return &ei->vfs_inode; 199 } 200 201 static void adfs_free_inode(struct inode *inode) 202 { 203 kmem_cache_free(adfs_inode_cachep, ADFS_I(inode)); 204 } 205 206 static int adfs_drop_inode(struct inode *inode) 207 { 208 /* always drop inodes if we are read-only */ 209 return !IS_ENABLED(CONFIG_ADFS_FS_RW) || IS_RDONLY(inode); 210 } 211 212 static void init_once(void *foo) 213 { 214 struct adfs_inode_info *ei = (struct adfs_inode_info *) foo; 215 216 inode_init_once(&ei->vfs_inode); 217 } 218 219 static int __init init_inodecache(void) 220 { 221 adfs_inode_cachep = kmem_cache_create("adfs_inode_cache", 222 sizeof(struct adfs_inode_info), 223 0, (SLAB_RECLAIM_ACCOUNT| 224 SLAB_ACCOUNT), 225 init_once); 226 if (adfs_inode_cachep == NULL) 227 return -ENOMEM; 228 return 0; 229 } 230 231 static void destroy_inodecache(void) 232 { 233 /* 234 * Make sure all delayed rcu free inodes are flushed before we 235 * destroy cache. 236 */ 237 rcu_barrier(); 238 kmem_cache_destroy(adfs_inode_cachep); 239 } 240 241 static const struct super_operations adfs_sops = { 242 .alloc_inode = adfs_alloc_inode, 243 .free_inode = adfs_free_inode, 244 .drop_inode = adfs_drop_inode, 245 .write_inode = adfs_write_inode, 246 .put_super = adfs_put_super, 247 .statfs = adfs_statfs, 248 .show_options = adfs_show_options, 249 }; 250 251 static int adfs_probe(struct super_block *sb, unsigned int offset, int silent, 252 int (*validate)(struct super_block *sb, 253 struct buffer_head *bh, 254 struct adfs_discrecord **bhp)) 255 { 256 struct adfs_sb_info *asb = ADFS_SB(sb); 257 struct adfs_discrecord *dr; 258 struct buffer_head *bh; 259 unsigned int blocksize = BLOCK_SIZE; 260 int ret, try; 261 262 for (try = 0; try < 2; try++) { 263 /* try to set the requested block size */ 264 if (sb->s_blocksize != blocksize && 265 !sb_set_blocksize(sb, blocksize)) { 266 if (!silent) 267 adfs_msg(sb, KERN_ERR, 268 "error: unsupported blocksize"); 269 return -EINVAL; 270 } 271 272 /* read the buffer */ 273 bh = sb_bread(sb, offset >> sb->s_blocksize_bits); 274 if (!bh) { 275 adfs_msg(sb, KERN_ERR, 276 "error: unable to read block %u, try %d", 277 offset >> sb->s_blocksize_bits, try); 278 return -EIO; 279 } 280 281 /* validate it */ 282 ret = validate(sb, bh, &dr); 283 if (ret) { 284 brelse(bh); 285 return ret; 286 } 287 288 /* does the block size match the filesystem block size? */ 289 blocksize = 1 << dr->log2secsize; 290 if (sb->s_blocksize == blocksize) { 291 asb->s_map = adfs_read_map(sb, dr); 292 brelse(bh); 293 return PTR_ERR_OR_ZERO(asb->s_map); 294 } 295 296 brelse(bh); 297 } 298 299 return -EIO; 300 } 301 302 static int adfs_validate_bblk(struct super_block *sb, struct buffer_head *bh, 303 struct adfs_discrecord **drp) 304 { 305 struct adfs_discrecord *dr; 306 unsigned char *b_data; 307 308 b_data = bh->b_data + (ADFS_DISCRECORD % sb->s_blocksize); 309 if (adfs_checkbblk(b_data)) 310 return -EILSEQ; 311 312 /* Do some sanity checks on the ADFS disc record */ 313 dr = (struct adfs_discrecord *)(b_data + ADFS_DR_OFFSET); 314 if (adfs_checkdiscrecord(dr)) 315 return -EILSEQ; 316 317 if ((dr->nzones | dr->nzones_high << 8) == 0) 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 return ret; 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 set_default_d_op(sb, &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 return -EIO; 407 } 408 return 0; 409 } 410 411 static int adfs_get_tree(struct fs_context *fc) 412 { 413 return get_tree_bdev(fc, adfs_fill_super); 414 } 415 416 static void adfs_free_fc(struct fs_context *fc) 417 { 418 struct adfs_context *asb = fc->s_fs_info; 419 420 kfree(asb); 421 } 422 423 static const struct fs_context_operations adfs_context_ops = { 424 .parse_param = adfs_parse_param, 425 .get_tree = adfs_get_tree, 426 .reconfigure = adfs_reconfigure, 427 .free = adfs_free_fc, 428 }; 429 430 static int adfs_init_fs_context(struct fs_context *fc) 431 { 432 struct adfs_sb_info *asb; 433 434 asb = kzalloc_obj(struct adfs_sb_info); 435 if (!asb) 436 return -ENOMEM; 437 438 if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE) { 439 struct super_block *sb = fc->root->d_sb; 440 struct adfs_sb_info *old_asb = ADFS_SB(sb); 441 442 /* structure copy existing options before parsing */ 443 *asb = *old_asb; 444 } else { 445 /* set default options */ 446 asb->s_uid = GLOBAL_ROOT_UID; 447 asb->s_gid = GLOBAL_ROOT_GID; 448 asb->s_owner_mask = ADFS_DEFAULT_OWNER_MASK; 449 asb->s_other_mask = ADFS_DEFAULT_OTHER_MASK; 450 asb->s_ftsuffix = 0; 451 } 452 453 fc->ops = &adfs_context_ops; 454 fc->s_fs_info = asb; 455 456 return 0; 457 } 458 459 static void adfs_kill_sb(struct super_block *sb) 460 { 461 struct adfs_sb_info *asb = ADFS_SB(sb); 462 463 kill_block_super(sb); 464 465 kfree_rcu(asb, rcu); 466 } 467 468 static struct file_system_type adfs_fs_type = { 469 .owner = THIS_MODULE, 470 .name = "adfs", 471 .kill_sb = adfs_kill_sb, 472 .fs_flags = FS_REQUIRES_DEV, 473 .init_fs_context = adfs_init_fs_context, 474 .parameters = adfs_param_spec, 475 }; 476 MODULE_ALIAS_FS("adfs"); 477 478 static int __init init_adfs_fs(void) 479 { 480 int err = init_inodecache(); 481 if (err) 482 goto out1; 483 err = register_filesystem(&adfs_fs_type); 484 if (err) 485 goto out; 486 return 0; 487 out: 488 destroy_inodecache(); 489 out1: 490 return err; 491 } 492 493 static void __exit exit_adfs_fs(void) 494 { 495 unregister_filesystem(&adfs_fs_type); 496 destroy_inodecache(); 497 } 498 499 module_init(init_adfs_fs) 500 module_exit(exit_adfs_fs) 501 MODULE_DESCRIPTION("Acorn Disc Filing System"); 502 MODULE_LICENSE("GPL"); 503