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