fs/adfs/super.c

   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 "adfs.h"
  16 #include "dir_f.h"
  17 #include "dir_fplus.h"
  18
  19 #define ADFS_SB_FLAGS SB_NOATIME
  20
  21 #define ADFS_DEFAULT_OWNER_MASK S_IRWXU
  22 #define ADFS_DEFAULT_OTHER_MASK (S_IRWXG | S_IRWXO)
  23
  24 void __adfs_error(struct super_block *sb, const char *function, const char *fmt, ...)
  25 {
  26         struct va_format vaf;
  27         va_list args;
  28
  29         va_start(args, fmt);
  30         vaf.fmt = fmt;
  31         vaf.va = &args;
  32
  33         printk(KERN_CRIT "ADFS-fs error (device %s)%s%s: %pV\n",
  34                 sb->s_id, function ? ": " : "",
  35                 function ? function : "", &vaf);
  36
  37         va_end(args);
  38 }
  39
  40 void adfs_msg(struct super_block *sb, const char *pfx, const char *fmt, ...)
  41 {
  42         struct va_format vaf;
  43         va_list args;
  44
  45         va_start(args, fmt);
  46         vaf.fmt = fmt;
  47         vaf.va = &args;
  48         printk("%sADFS-fs (%s): %pV\n", pfx, sb->s_id, &vaf);
  49         va_end(args);
  50 }
  51
  52 static int adfs_checkdiscrecord(struct adfs_discrecord *dr)
  53 {
  54         unsigned int max_idlen;
  55         int i;
  56
  57         /* sector size must be 256, 512 or 1024 bytes */
  58         if (dr->log2secsize != 8 &&
  59             dr->log2secsize != 9 &&
  60             dr->log2secsize != 10)
  61                 return 1;
  62
  63         /* idlen must be at least log2secsize + 3 */
  64         if (dr->idlen < dr->log2secsize + 3)
  65                 return 1;
  66
  67         /* we cannot have such a large disc that we
  68          * are unable to represent sector offsets in
  69          * 32 bits.  This works out at 2.0 TB.
  70          */
  71         if (le32_to_cpu(dr->disc_size_high) >> dr->log2secsize)
  72                 return 1;
  73
  74         /*
  75          * Maximum idlen is limited to 16 bits for new directories by
  76          * the three-byte storage of an indirect disc address.  For
  77          * big directories, idlen must be no greater than 19 v2 [1.0]
  78          */
  79         max_idlen = dr->format_version ? 19 : 16;
  80         if (dr->idlen > max_idlen)
  81                 return 1;
  82
  83         /* reserved bytes should be zero */
  84         for (i = 0; i < sizeof(dr->unused52); i++)
  85                 if (dr->unused52[i] != 0)
  86                         return 1;
  87
  88         return 0;
  89 }
  90
  91 static void adfs_put_super(struct super_block *sb)
  92 {
  93         struct adfs_sb_info *asb = ADFS_SB(sb);
  94
  95         adfs_free_map(sb);
  96         kfree_rcu(asb, rcu);
  97 }
  98
  99 static int adfs_show_options(struct seq_file *seq, struct dentry *root)
 100 {
 101         struct adfs_sb_info *asb = ADFS_SB(root->d_sb);
 102
 103         if (!uid_eq(asb->s_uid, GLOBAL_ROOT_UID))
 104                 seq_printf(seq, ",uid=%u", from_kuid_munged(&init_user_ns, asb->s_uid));
 105         if (!gid_eq(asb->s_gid, GLOBAL_ROOT_GID))
 106                 seq_printf(seq, ",gid=%u", from_kgid_munged(&init_user_ns, asb->s_gid));
 107         if (asb->s_owner_mask != ADFS_DEFAULT_OWNER_MASK)
 108                 seq_printf(seq, ",ownmask=%o", asb->s_owner_mask);
 109         if (asb->s_other_mask != ADFS_DEFAULT_OTHER_MASK)
 110                 seq_printf(seq, ",othmask=%o", asb->s_other_mask);
 111         if (asb->s_ftsuffix != 0)
 112                 seq_printf(seq, ",ftsuffix=%u", asb->s_ftsuffix);
 113
 114         return 0;
 115 }
 116
 117 enum {Opt_uid, Opt_gid, Opt_ownmask, Opt_othmask, Opt_ftsuffix, Opt_err};
 118
 119 static const match_table_t tokens = {
 120         {Opt_uid, "uid=%u"},
 121         {Opt_gid, "gid=%u"},
 122         {Opt_ownmask, "ownmask=%o"},
 123         {Opt_othmask, "othmask=%o"},
 124         {Opt_ftsuffix, "ftsuffix=%u"},
 125         {Opt_err, NULL}
 126 };
 127
 128 static int parse_options(struct super_block *sb, struct adfs_sb_info *asb,
 129                          char *options)
 130 {
 131         char *p;
 132         int option;
 133
 134         if (!options)
 135                 return 0;
 136
 137         while ((p = strsep(&options, ",")) != NULL) {
 138                 substring_t args[MAX_OPT_ARGS];
 139                 int token;
 140                 if (!*p)
 141                         continue;
 142
 143                 token = match_token(p, tokens, args);
 144                 switch (token) {
 145                 case Opt_uid:
 146                         if (match_int(args, &option))
 147                                 return -EINVAL;
 148                         asb->s_uid = make_kuid(current_user_ns(), option);
 149                         if (!uid_valid(asb->s_uid))
 150                                 return -EINVAL;
 151                         break;
 152                 case Opt_gid:
 153                         if (match_int(args, &option))
 154                                 return -EINVAL;
 155                         asb->s_gid = make_kgid(current_user_ns(), option);
 156                         if (!gid_valid(asb->s_gid))
 157                                 return -EINVAL;
 158                         break;
 159                 case Opt_ownmask:
 160                         if (match_octal(args, &option))
 161                                 return -EINVAL;
 162                         asb->s_owner_mask = option;
 163                         break;
 164                 case Opt_othmask:
 165                         if (match_octal(args, &option))
 166                                 return -EINVAL;
 167                         asb->s_other_mask = option;
 168                         break;
 169                 case Opt_ftsuffix:
 170                         if (match_int(args, &option))
 171                                 return -EINVAL;
 172                         asb->s_ftsuffix = option;
 173                         break;
 174                 default:
 175                         adfs_msg(sb, KERN_ERR,
 176                                  "unrecognised mount option \"%s\" or missing value",
 177                                  p);
 178                         return -EINVAL;
 179                 }
 180         }
 181         return 0;
 182 }
 183
 184 static int adfs_remount(struct super_block *sb, int *flags, char *data)
 185 {
 186         struct adfs_sb_info temp_asb;
 187         int ret;
 188
 189         sync_filesystem(sb);
 190         *flags |= ADFS_SB_FLAGS;
 191
 192         temp_asb = *ADFS_SB(sb);
 193         ret = parse_options(sb, &temp_asb, data);
 194         if (ret == 0)
 195                 *ADFS_SB(sb) = temp_asb;
 196
 197         return ret;
 198 }
 199
 200 static int adfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 201 {
 202         struct super_block *sb = dentry->d_sb;
 203         struct adfs_sb_info *sbi = ADFS_SB(sb);
 204         u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
 205
 206         adfs_map_statfs(sb, buf);
 207
 208         buf->f_type    = ADFS_SUPER_MAGIC;
 209         buf->f_namelen = sbi->s_namelen;
 210         buf->f_bsize   = sb->s_blocksize;
 211         buf->f_ffree   = (long)(buf->f_bfree * buf->f_files) / (long)buf->f_blocks;
 212         buf->f_fsid.val[0] = (u32)id;
 213         buf->f_fsid.val[1] = (u32)(id >> 32);
 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 = kmem_cache_alloc(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_MEM_SPREAD|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_LICENSE("GPL");