fs/adfs/super.c

   1 /*
   2  *  linux/fs/adfs/super.c
   3  *
   4  *  Copyright (C) 1997-1999 Russell King
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation.
   9  */
  10 #include <linux/module.h>
  11 #include <linux/errno.h>
  12 #include <linux/fs.h>
  13 #include <linux/adfs_fs.h>
  14 #include <linux/slab.h>
  15 #include <linux/time.h>
  16 #include <linux/stat.h>
  17 #include <linux/string.h>
  18 #include <linux/init.h>
  19 #include <linux/buffer_head.h>
  20 #include <linux/vfs.h>
  21 #include <linux/parser.h>
  22 #include <linux/bitops.h>
  23 #include <linux/mount.h>
  24 #include <linux/seq_file.h>
  25
  26 #include <asm/uaccess.h>
  27 #include <asm/system.h>
  28
  29 #include <stdarg.h>
  30
  31 #include "adfs.h"
  32 #include "dir_f.h"
  33 #include "dir_fplus.h"
  34
  35 #define ADFS_DEFAULT_OWNER_MASK S_IRWXU
  36 #define ADFS_DEFAULT_OTHER_MASK (S_IRWXG | S_IRWXO)
  37
  38 void __adfs_error(struct super_block *sb, const char *function, const char *fmt, ...)
  39 {
  40         char error_buf[128];
  41         va_list args;
  42
  43         va_start(args, fmt);
  44         vsnprintf(error_buf, sizeof(error_buf), fmt, args);
  45         va_end(args);
  46
  47         printk(KERN_CRIT "ADFS-fs error (device %s)%s%s: %s\n",
  48                 sb->s_id, function ? ": " : "",
  49                 function ? function : "", error_buf);
  50 }
  51
  52 static int adfs_checkdiscrecord(struct adfs_discrecord *dr)
  53 {
  54         int i;
  55
  56         /* sector size must be 256, 512 or 1024 bytes */
  57         if (dr->log2secsize != 8 &&
  58             dr->log2secsize != 9 &&
  59             dr->log2secsize != 10)
  60                 return 1;
  61
  62         /* idlen must be at least log2secsize + 3 */
  63         if (dr->idlen < dr->log2secsize + 3)
  64                 return 1;
  65
  66         /* we cannot have such a large disc that we
  67          * are unable to represent sector offsets in
  68          * 32 bits.  This works out at 2.0 TB.
  69          */
  70         if (le32_to_cpu(dr->disc_size_high) >> dr->log2secsize)
  71                 return 1;
  72
  73         /* idlen must be no greater than 19 v2 [1.0] */
  74         if (dr->idlen > 19)
  75                 return 1;
  76
  77         /* reserved bytes should be zero */
  78         for (i = 0; i < sizeof(dr->unused52); i++)
  79                 if (dr->unused52[i] != 0)
  80                         return 1;
  81
  82         return 0;
  83 }
  84
  85 static unsigned char adfs_calczonecheck(struct super_block *sb, unsigned char *map)
  86 {
  87         unsigned int v0, v1, v2, v3;
  88         int i;
  89
  90         v0 = v1 = v2 = v3 = 0;
  91         for (i = sb->s_blocksize - 4; i; i -= 4) {
  92                 v0 += map[i]     + (v3 >> 8);
  93                 v3 &= 0xff;
  94                 v1 += map[i + 1] + (v0 >> 8);
  95                 v0 &= 0xff;
  96                 v2 += map[i + 2] + (v1 >> 8);
  97                 v1 &= 0xff;
  98                 v3 += map[i + 3] + (v2 >> 8);
  99                 v2 &= 0xff;
 100         }
 101         v0 +=           v3 >> 8;
 102         v1 += map[1] + (v0 >> 8);
 103         v2 += map[2] + (v1 >> 8);
 104         v3 += map[3] + (v2 >> 8);
 105
 106         return v0 ^ v1 ^ v2 ^ v3;
 107 }
 108
 109 static int adfs_checkmap(struct super_block *sb, struct adfs_discmap *dm)
 110 {
 111         unsigned char crosscheck = 0, zonecheck = 1;
 112         int i;
 113
 114         for (i = 0; i < ADFS_SB(sb)->s_map_size; i++) {
 115                 unsigned char *map;
 116
 117                 map = dm[i].dm_bh->b_data;
 118
 119                 if (adfs_calczonecheck(sb, map) != map[0]) {
 120                         adfs_error(sb, "zone %d fails zonecheck", i);
 121                         zonecheck = 0;
 122                 }
 123                 crosscheck ^= map[3];
 124         }
 125         if (crosscheck != 0xff)
 126                 adfs_error(sb, "crosscheck != 0xff");
 127         return crosscheck == 0xff && zonecheck;
 128 }
 129
 130 static void adfs_put_super(struct super_block *sb)
 131 {
 132         int i;
 133         struct adfs_sb_info *asb = ADFS_SB(sb);
 134
 135         for (i = 0; i < asb->s_map_size; i++)
 136                 brelse(asb->s_map[i].dm_bh);
 137         kfree(asb->s_map);
 138         kfree(asb);
 139         sb->s_fs_info = NULL;
 140 }
 141
 142 static int adfs_show_options(struct seq_file *seq, struct vfsmount *mnt)
 143 {
 144         struct adfs_sb_info *asb = ADFS_SB(mnt->mnt_sb);
 145
 146         if (asb->s_uid != 0)
 147                 seq_printf(seq, ",uid=%u", asb->s_uid);
 148         if (asb->s_gid != 0)
 149                 seq_printf(seq, ",gid=%u", asb->s_gid);
 150         if (asb->s_owner_mask != ADFS_DEFAULT_OWNER_MASK)
 151                 seq_printf(seq, ",ownmask=%o", asb->s_owner_mask);
 152         if (asb->s_other_mask != ADFS_DEFAULT_OTHER_MASK)
 153                 seq_printf(seq, ",othmask=%o", asb->s_other_mask);
 154
 155         return 0;
 156 }
 157
 158 enum {Opt_uid, Opt_gid, Opt_ownmask, Opt_othmask, Opt_err};
 159
 160 static const match_table_t tokens = {
 161         {Opt_uid, "uid=%u"},
 162         {Opt_gid, "gid=%u"},
 163         {Opt_ownmask, "ownmask=%o"},
 164         {Opt_othmask, "othmask=%o"},
 165         {Opt_err, NULL}
 166 };
 167
 168 static int parse_options(struct super_block *sb, char *options)
 169 {
 170         char *p;
 171         struct adfs_sb_info *asb = ADFS_SB(sb);
 172         int option;
 173
 174         if (!options)
 175                 return 0;
 176
 177         while ((p = strsep(&options, ",")) != NULL) {
 178                 substring_t args[MAX_OPT_ARGS];
 179                 int token;
 180                 if (!*p)
 181                         continue;
 182
 183                 token = match_token(p, tokens, args);
 184                 switch (token) {
 185                 case Opt_uid:
 186                         if (match_int(args, &option))
 187                                 return -EINVAL;
 188                         asb->s_uid = option;
 189                         break;
 190                 case Opt_gid:
 191                         if (match_int(args, &option))
 192                                 return -EINVAL;
 193                         asb->s_gid = option;
 194                         break;
 195                 case Opt_ownmask:
 196                         if (match_octal(args, &option))
 197                                 return -EINVAL;
 198                         asb->s_owner_mask = option;
 199                         break;
 200                 case Opt_othmask:
 201                         if (match_octal(args, &option))
 202                                 return -EINVAL;
 203                         asb->s_other_mask = option;
 204                         break;
 205                 default:
 206                         printk("ADFS-fs: unrecognised mount option \"%s\" "
 207                                         "or missing value\n", p);
 208                         return -EINVAL;
 209                 }
 210         }
 211         return 0;
 212 }
 213
 214 static int adfs_remount(struct super_block *sb, int *flags, char *data)
 215 {
 216         *flags |= MS_NODIRATIME;
 217         return parse_options(sb, data);
 218 }
 219
 220 static int adfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 221 {
 222         struct super_block *sb = dentry->d_sb;
 223         struct adfs_sb_info *sbi = ADFS_SB(sb);
 224         u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
 225
 226         buf->f_type    = ADFS_SUPER_MAGIC;
 227         buf->f_namelen = sbi->s_namelen;
 228         buf->f_bsize   = sb->s_blocksize;
 229         buf->f_blocks  = sbi->s_size;
 230         buf->f_files   = sbi->s_ids_per_zone * sbi->s_map_size;
 231         buf->f_bavail  =
 232         buf->f_bfree   = adfs_map_free(sb);
 233         buf->f_ffree   = (long)(buf->f_bfree * buf->f_files) / (long)buf->f_blocks;
 234         buf->f_fsid.val[0] = (u32)id;
 235         buf->f_fsid.val[1] = (u32)(id >> 32);
 236
 237         return 0;
 238 }
 239
 240 static struct kmem_cache *adfs_inode_cachep;
 241
 242 static struct inode *adfs_alloc_inode(struct super_block *sb)
 243 {
 244         struct adfs_inode_info *ei;
 245         ei = (struct adfs_inode_info *)kmem_cache_alloc(adfs_inode_cachep, GFP_KERNEL);
 246         if (!ei)
 247                 return NULL;
 248         return &ei->vfs_inode;
 249 }
 250
 251 static void adfs_destroy_inode(struct inode *inode)
 252 {
 253         kmem_cache_free(adfs_inode_cachep, ADFS_I(inode));
 254 }
 255
 256 static void init_once(void *foo)
 257 {
 258         struct adfs_inode_info *ei = (struct adfs_inode_info *) foo;
 259
 260         inode_init_once(&ei->vfs_inode);
 261 }
 262
 263 static int init_inodecache(void)
 264 {
 265         adfs_inode_cachep = kmem_cache_create("adfs_inode_cache",
 266                                              sizeof(struct adfs_inode_info),
 267                                              0, (SLAB_RECLAIM_ACCOUNT|
 268                                                 SLAB_MEM_SPREAD),
 269                                              init_once);
 270         if (adfs_inode_cachep == NULL)
 271                 return -ENOMEM;
 272         return 0;
 273 }
 274
 275 static void destroy_inodecache(void)
 276 {
 277         kmem_cache_destroy(adfs_inode_cachep);
 278 }
 279
 280 static const struct super_operations adfs_sops = {
 281         .alloc_inode    = adfs_alloc_inode,
 282         .destroy_inode  = adfs_destroy_inode,
 283         .write_inode    = adfs_write_inode,
 284         .put_super      = adfs_put_super,
 285         .statfs         = adfs_statfs,
 286         .remount_fs     = adfs_remount,
 287         .show_options   = adfs_show_options,
 288 };
 289
 290 static struct adfs_discmap *adfs_read_map(struct super_block *sb, struct adfs_discrecord *dr)
 291 {
 292         struct adfs_discmap *dm;
 293         unsigned int map_addr, zone_size, nzones;
 294         int i, zone;
 295         struct adfs_sb_info *asb = ADFS_SB(sb);
 296
 297         nzones    = asb->s_map_size;
 298         zone_size = (8 << dr->log2secsize) - le16_to_cpu(dr->zone_spare);
 299         map_addr  = (nzones >> 1) * zone_size -
 300                      ((nzones > 1) ? ADFS_DR_SIZE_BITS : 0);
 301         map_addr  = signed_asl(map_addr, asb->s_map2blk);
 302
 303         asb->s_ids_per_zone = zone_size / (asb->s_idlen + 1);
 304
 305         dm = kmalloc(nzones * sizeof(*dm), GFP_KERNEL);
 306         if (dm == NULL) {
 307                 adfs_error(sb, "not enough memory");
 308                 return NULL;
 309         }
 310
 311         for (zone = 0; zone < nzones; zone++, map_addr++) {
 312                 dm[zone].dm_startbit = 0;
 313                 dm[zone].dm_endbit   = zone_size;
 314                 dm[zone].dm_startblk = zone * zone_size - ADFS_DR_SIZE_BITS;
 315                 dm[zone].dm_bh       = sb_bread(sb, map_addr);
 316
 317                 if (!dm[zone].dm_bh) {
 318                         adfs_error(sb, "unable to read map");
 319                         goto error_free;
 320                 }
 321         }
 322
 323         /* adjust the limits for the first and last map zones */
 324         i = zone - 1;
 325         dm[0].dm_startblk = 0;
 326         dm[0].dm_startbit = ADFS_DR_SIZE_BITS;
 327         dm[i].dm_endbit   = (le32_to_cpu(dr->disc_size_high) << (32 - dr->log2bpmb)) +
 328                             (le32_to_cpu(dr->disc_size) >> dr->log2bpmb) +
 329                             (ADFS_DR_SIZE_BITS - i * zone_size);
 330
 331         if (adfs_checkmap(sb, dm))
 332                 return dm;
 333
 334         adfs_error(sb, "map corrupted");
 335
 336 error_free:
 337         while (--zone >= 0)
 338                 brelse(dm[zone].dm_bh);
 339
 340         kfree(dm);
 341         return NULL;
 342 }
 343
 344 static inline unsigned long adfs_discsize(struct adfs_discrecord *dr, int block_bits)
 345 {
 346         unsigned long discsize;
 347
 348         discsize  = le32_to_cpu(dr->disc_size_high) << (32 - block_bits);
 349         discsize |= le32_to_cpu(dr->disc_size) >> block_bits;
 350
 351         return discsize;
 352 }
 353
 354 static int adfs_fill_super(struct super_block *sb, void *data, int silent)
 355 {
 356         struct adfs_discrecord *dr;
 357         struct buffer_head *bh;
 358         struct object_info root_obj;
 359         unsigned char *b_data;
 360         struct adfs_sb_info *asb;
 361         struct inode *root;
 362
 363         sb->s_flags |= MS_NODIRATIME;
 364
 365         asb = kzalloc(sizeof(*asb), GFP_KERNEL);
 366         if (!asb)
 367                 return -ENOMEM;
 368         sb->s_fs_info = asb;
 369
 370         /* set default options */
 371         asb->s_uid = 0;
 372         asb->s_gid = 0;
 373         asb->s_owner_mask = ADFS_DEFAULT_OWNER_MASK;
 374         asb->s_other_mask = ADFS_DEFAULT_OTHER_MASK;
 375
 376         if (parse_options(sb, data))
 377                 goto error;
 378
 379         sb_set_blocksize(sb, BLOCK_SIZE);
 380         if (!(bh = sb_bread(sb, ADFS_DISCRECORD / BLOCK_SIZE))) {
 381                 adfs_error(sb, "unable to read superblock");
 382                 goto error;
 383         }
 384
 385         b_data = bh->b_data + (ADFS_DISCRECORD % BLOCK_SIZE);
 386
 387         if (adfs_checkbblk(b_data)) {
 388                 if (!silent)
 389                         printk("VFS: Can't find an adfs filesystem on dev "
 390                                 "%s.\n", sb->s_id);
 391                 goto error_free_bh;
 392         }
 393
 394         dr = (struct adfs_discrecord *)(b_data + ADFS_DR_OFFSET);
 395
 396         /*
 397          * Do some sanity checks on the ADFS disc record
 398          */
 399         if (adfs_checkdiscrecord(dr)) {
 400                 if (!silent)
 401                         printk("VPS: Can't find an adfs filesystem on dev "
 402                                 "%s.\n", sb->s_id);
 403                 goto error_free_bh;
 404         }
 405
 406         brelse(bh);
 407         if (sb_set_blocksize(sb, 1 << dr->log2secsize)) {
 408                 bh = sb_bread(sb, ADFS_DISCRECORD / sb->s_blocksize);
 409                 if (!bh) {
 410                         adfs_error(sb, "couldn't read superblock on "
 411                                 "2nd try.");
 412                         goto error;
 413                 }
 414                 b_data = bh->b_data + (ADFS_DISCRECORD % sb->s_blocksize);
 415                 if (adfs_checkbblk(b_data)) {
 416                         adfs_error(sb, "disc record mismatch, very weird!");
 417                         goto error_free_bh;
 418                 }
 419                 dr = (struct adfs_discrecord *)(b_data + ADFS_DR_OFFSET);
 420         } else {
 421                 if (!silent)
 422                         printk(KERN_ERR "VFS: Unsupported blocksize on dev "
 423                                 "%s.\n", sb->s_id);
 424                 goto error;
 425         }
 426
 427         /*
 428          * blocksize on this device should now be set to the ADFS log2secsize
 429          */
 430
 431         sb->s_magic             = ADFS_SUPER_MAGIC;
 432         asb->s_idlen            = dr->idlen;
 433         asb->s_map_size         = dr->nzones | (dr->nzones_high << 8);
 434         asb->s_map2blk          = dr->log2bpmb - dr->log2secsize;
 435         asb->s_size             = adfs_discsize(dr, sb->s_blocksize_bits);
 436         asb->s_version          = dr->format_version;
 437         asb->s_log2sharesize    = dr->log2sharesize;
 438
 439         asb->s_map = adfs_read_map(sb, dr);
 440         if (!asb->s_map)
 441                 goto error_free_bh;
 442
 443         brelse(bh);
 444
 445         /*
 446          * set up enough so that we can read an inode
 447          */
 448         sb->s_op = &adfs_sops;
 449
 450         dr = (struct adfs_discrecord *)(asb->s_map[0].dm_bh->b_data + 4);
 451
 452         root_obj.parent_id = root_obj.file_id = le32_to_cpu(dr->root);
 453         root_obj.name_len  = 0;
 454         root_obj.loadaddr  = 0;
 455         root_obj.execaddr  = 0;
 456         root_obj.size      = ADFS_NEWDIR_SIZE;
 457         root_obj.attr      = ADFS_NDA_DIRECTORY   | ADFS_NDA_OWNER_READ |
 458                              ADFS_NDA_OWNER_WRITE | ADFS_NDA_PUBLIC_READ;
 459
 460         /*
 461          * If this is a F+ disk with variable length directories,
 462          * get the root_size from the disc record.
 463          */
 464         if (asb->s_version) {
 465                 root_obj.size = le32_to_cpu(dr->root_size);
 466                 asb->s_dir     = &adfs_fplus_dir_ops;
 467                 asb->s_namelen = ADFS_FPLUS_NAME_LEN;
 468         } else {
 469                 asb->s_dir     = &adfs_f_dir_ops;
 470                 asb->s_namelen = ADFS_F_NAME_LEN;
 471         }
 472
 473         root = adfs_iget(sb, &root_obj);
 474         sb->s_root = d_alloc_root(root);
 475         if (!sb->s_root) {
 476                 int i;
 477                 iput(root);
 478                 for (i = 0; i < asb->s_map_size; i++)
 479                         brelse(asb->s_map[i].dm_bh);
 480                 kfree(asb->s_map);
 481                 adfs_error(sb, "get root inode failed\n");
 482                 goto error;
 483         } else
 484                 sb->s_root->d_op = &adfs_dentry_operations;
 485         return 0;
 486
 487 error_free_bh:
 488         brelse(bh);
 489 error:
 490         sb->s_fs_info = NULL;
 491         kfree(asb);
 492         return -EINVAL;
 493 }
 494
 495 static int adfs_get_sb(struct file_system_type *fs_type,
 496         int flags, const char *dev_name, void *data, struct vfsmount *mnt)
 497 {
 498         return get_sb_bdev(fs_type, flags, dev_name, data, adfs_fill_super,
 499                            mnt);
 500 }
 501
 502 static struct file_system_type adfs_fs_type = {
 503         .owner          = THIS_MODULE,
 504         .name           = "adfs",
 505         .get_sb         = adfs_get_sb,
 506         .kill_sb        = kill_block_super,
 507         .fs_flags       = FS_REQUIRES_DEV,
 508 };
 509
 510 static int __init init_adfs_fs(void)
 511 {
 512         int err = init_inodecache();
 513         if (err)
 514                 goto out1;
 515         err = register_filesystem(&adfs_fs_type);
 516         if (err)
 517                 goto out;
 518         return 0;
 519 out:
 520         destroy_inodecache();
 521 out1:
 522         return err;
 523 }
 524
 525 static void __exit exit_adfs_fs(void)
 526 {
 527         unregister_filesystem(&adfs_fs_type);
 528         destroy_inodecache();
 529 }
 530
 531 module_init(init_adfs_fs)
 532 module_exit(exit_adfs_fs)