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         lock_kernel();
 136
 137         for (i = 0; i < asb->s_map_size; i++)
 138                 brelse(asb->s_map[i].dm_bh);
 139         kfree(asb->s_map);
 140         kfree(asb);
 141         sb->s_fs_info = NULL;
 142
 143         unlock_kernel();
 144 }
 145
 146 static int adfs_show_options(struct seq_file *seq, struct vfsmount *mnt)
 147 {
 148         struct adfs_sb_info *asb = ADFS_SB(mnt->mnt_sb);
 149
 150         if (asb->s_uid != 0)
 151                 seq_printf(seq, ",uid=%u", asb->s_uid);
 152         if (asb->s_gid != 0)
 153                 seq_printf(seq, ",gid=%u", asb->s_gid);
 154         if (asb->s_owner_mask != ADFS_DEFAULT_OWNER_MASK)
 155                 seq_printf(seq, ",ownmask=%o", asb->s_owner_mask);
 156         if (asb->s_other_mask != ADFS_DEFAULT_OTHER_MASK)
 157                 seq_printf(seq, ",othmask=%o", asb->s_other_mask);
 158
 159         return 0;
 160 }
 161
 162 enum {Opt_uid, Opt_gid, Opt_ownmask, Opt_othmask, Opt_err};
 163
 164 static const match_table_t tokens = {
 165         {Opt_uid, "uid=%u"},
 166         {Opt_gid, "gid=%u"},
 167         {Opt_ownmask, "ownmask=%o"},
 168         {Opt_othmask, "othmask=%o"},
 169         {Opt_err, NULL}
 170 };
 171
 172 static int parse_options(struct super_block *sb, char *options)
 173 {
 174         char *p;
 175         struct adfs_sb_info *asb = ADFS_SB(sb);
 176         int option;
 177
 178         if (!options)
 179                 return 0;
 180
 181         while ((p = strsep(&options, ",")) != NULL) {
 182                 substring_t args[MAX_OPT_ARGS];
 183                 int token;
 184                 if (!*p)
 185                         continue;
 186
 187                 token = match_token(p, tokens, args);
 188                 switch (token) {
 189                 case Opt_uid:
 190                         if (match_int(args, &option))
 191                                 return -EINVAL;
 192                         asb->s_uid = option;
 193                         break;
 194                 case Opt_gid:
 195                         if (match_int(args, &option))
 196                                 return -EINVAL;
 197                         asb->s_gid = option;
 198                         break;
 199                 case Opt_ownmask:
 200                         if (match_octal(args, &option))
 201                                 return -EINVAL;
 202                         asb->s_owner_mask = option;
 203                         break;
 204                 case Opt_othmask:
 205                         if (match_octal(args, &option))
 206                                 return -EINVAL;
 207                         asb->s_other_mask = option;
 208                         break;
 209                 default:
 210                         printk("ADFS-fs: unrecognised mount option \"%s\" "
 211                                         "or missing value\n", p);
 212                         return -EINVAL;
 213                 }
 214         }
 215         return 0;
 216 }
 217
 218 static int adfs_remount(struct super_block *sb, int *flags, char *data)
 219 {
 220         *flags |= MS_NODIRATIME;
 221         return parse_options(sb, data);
 222 }
 223
 224 static int adfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 225 {
 226         struct super_block *sb = dentry->d_sb;
 227         struct adfs_sb_info *sbi = ADFS_SB(sb);
 228         u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
 229
 230         buf->f_type    = ADFS_SUPER_MAGIC;
 231         buf->f_namelen = sbi->s_namelen;
 232         buf->f_bsize   = sb->s_blocksize;
 233         buf->f_blocks  = sbi->s_size;
 234         buf->f_files   = sbi->s_ids_per_zone * sbi->s_map_size;
 235         buf->f_bavail  =
 236         buf->f_bfree   = adfs_map_free(sb);
 237         buf->f_ffree   = (long)(buf->f_bfree * buf->f_files) / (long)buf->f_blocks;
 238         buf->f_fsid.val[0] = (u32)id;
 239         buf->f_fsid.val[1] = (u32)(id >> 32);
 240
 241         return 0;
 242 }
 243
 244 static struct kmem_cache *adfs_inode_cachep;
 245
 246 static struct inode *adfs_alloc_inode(struct super_block *sb)
 247 {
 248         struct adfs_inode_info *ei;
 249         ei = (struct adfs_inode_info *)kmem_cache_alloc(adfs_inode_cachep, GFP_KERNEL);
 250         if (!ei)
 251                 return NULL;
 252         return &ei->vfs_inode;
 253 }
 254
 255 static void adfs_destroy_inode(struct inode *inode)
 256 {
 257         kmem_cache_free(adfs_inode_cachep, ADFS_I(inode));
 258 }
 259
 260 static void init_once(void *foo)
 261 {
 262         struct adfs_inode_info *ei = (struct adfs_inode_info *) foo;
 263
 264         inode_init_once(&ei->vfs_inode);
 265 }
 266
 267 static int init_inodecache(void)
 268 {
 269         adfs_inode_cachep = kmem_cache_create("adfs_inode_cache",
 270                                              sizeof(struct adfs_inode_info),
 271                                              0, (SLAB_RECLAIM_ACCOUNT|
 272                                                 SLAB_MEM_SPREAD),
 273                                              init_once);
 274         if (adfs_inode_cachep == NULL)
 275                 return -ENOMEM;
 276         return 0;
 277 }
 278
 279 static void destroy_inodecache(void)
 280 {
 281         kmem_cache_destroy(adfs_inode_cachep);
 282 }
 283
 284 static const struct super_operations adfs_sops = {
 285         .alloc_inode    = adfs_alloc_inode,
 286         .destroy_inode  = adfs_destroy_inode,
 287         .write_inode    = adfs_write_inode,
 288         .put_super      = adfs_put_super,
 289         .statfs         = adfs_statfs,
 290         .remount_fs     = adfs_remount,
 291         .show_options   = adfs_show_options,
 292 };
 293
 294 static struct adfs_discmap *adfs_read_map(struct super_block *sb, struct adfs_discrecord *dr)
 295 {
 296         struct adfs_discmap *dm;
 297         unsigned int map_addr, zone_size, nzones;
 298         int i, zone;
 299         struct adfs_sb_info *asb = ADFS_SB(sb);
 300
 301         nzones    = asb->s_map_size;
 302         zone_size = (8 << dr->log2secsize) - le16_to_cpu(dr->zone_spare);
 303         map_addr  = (nzones >> 1) * zone_size -
 304                      ((nzones > 1) ? ADFS_DR_SIZE_BITS : 0);
 305         map_addr  = signed_asl(map_addr, asb->s_map2blk);
 306
 307         asb->s_ids_per_zone = zone_size / (asb->s_idlen + 1);
 308
 309         dm = kmalloc(nzones * sizeof(*dm), GFP_KERNEL);
 310         if (dm == NULL) {
 311                 adfs_error(sb, "not enough memory");
 312                 return NULL;
 313         }
 314
 315         for (zone = 0; zone < nzones; zone++, map_addr++) {
 316                 dm[zone].dm_startbit = 0;
 317                 dm[zone].dm_endbit   = zone_size;
 318                 dm[zone].dm_startblk = zone * zone_size - ADFS_DR_SIZE_BITS;
 319                 dm[zone].dm_bh       = sb_bread(sb, map_addr);
 320
 321                 if (!dm[zone].dm_bh) {
 322                         adfs_error(sb, "unable to read map");
 323                         goto error_free;
 324                 }
 325         }
 326
 327         /* adjust the limits for the first and last map zones */
 328         i = zone - 1;
 329         dm[0].dm_startblk = 0;
 330         dm[0].dm_startbit = ADFS_DR_SIZE_BITS;
 331         dm[i].dm_endbit   = (le32_to_cpu(dr->disc_size_high) << (32 - dr->log2bpmb)) +
 332                             (le32_to_cpu(dr->disc_size) >> dr->log2bpmb) +
 333                             (ADFS_DR_SIZE_BITS - i * zone_size);
 334
 335         if (adfs_checkmap(sb, dm))
 336                 return dm;
 337
 338         adfs_error(sb, "map corrupted");
 339
 340 error_free:
 341         while (--zone >= 0)
 342                 brelse(dm[zone].dm_bh);
 343
 344         kfree(dm);
 345         return NULL;
 346 }
 347
 348 static inline unsigned long adfs_discsize(struct adfs_discrecord *dr, int block_bits)
 349 {
 350         unsigned long discsize;
 351
 352         discsize  = le32_to_cpu(dr->disc_size_high) << (32 - block_bits);
 353         discsize |= le32_to_cpu(dr->disc_size) >> block_bits;
 354
 355         return discsize;
 356 }
 357
 358 static int adfs_fill_super(struct super_block *sb, void *data, int silent)
 359 {
 360         struct adfs_discrecord *dr;
 361         struct buffer_head *bh;
 362         struct object_info root_obj;
 363         unsigned char *b_data;
 364         struct adfs_sb_info *asb;
 365         struct inode *root;
 366
 367         sb->s_flags |= MS_NODIRATIME;
 368
 369         asb = kzalloc(sizeof(*asb), GFP_KERNEL);
 370         if (!asb)
 371                 return -ENOMEM;
 372         sb->s_fs_info = asb;
 373
 374         /* set default options */
 375         asb->s_uid = 0;
 376         asb->s_gid = 0;
 377         asb->s_owner_mask = ADFS_DEFAULT_OWNER_MASK;
 378         asb->s_other_mask = ADFS_DEFAULT_OTHER_MASK;
 379
 380         if (parse_options(sb, data))
 381                 goto error;
 382
 383         sb_set_blocksize(sb, BLOCK_SIZE);
 384         if (!(bh = sb_bread(sb, ADFS_DISCRECORD / BLOCK_SIZE))) {
 385                 adfs_error(sb, "unable to read superblock");
 386                 goto error;
 387         }
 388
 389         b_data = bh->b_data + (ADFS_DISCRECORD % BLOCK_SIZE);
 390
 391         if (adfs_checkbblk(b_data)) {
 392                 if (!silent)
 393                         printk("VFS: Can't find an adfs filesystem on dev "
 394                                 "%s.\n", sb->s_id);
 395                 goto error_free_bh;
 396         }
 397
 398         dr = (struct adfs_discrecord *)(b_data + ADFS_DR_OFFSET);
 399
 400         /*
 401          * Do some sanity checks on the ADFS disc record
 402          */
 403         if (adfs_checkdiscrecord(dr)) {
 404                 if (!silent)
 405                         printk("VPS: Can't find an adfs filesystem on dev "
 406                                 "%s.\n", sb->s_id);
 407                 goto error_free_bh;
 408         }
 409
 410         brelse(bh);
 411         if (sb_set_blocksize(sb, 1 << dr->log2secsize)) {
 412                 bh = sb_bread(sb, ADFS_DISCRECORD / sb->s_blocksize);
 413                 if (!bh) {
 414                         adfs_error(sb, "couldn't read superblock on "
 415                                 "2nd try.");
 416                         goto error;
 417                 }
 418                 b_data = bh->b_data + (ADFS_DISCRECORD % sb->s_blocksize);
 419                 if (adfs_checkbblk(b_data)) {
 420                         adfs_error(sb, "disc record mismatch, very weird!");
 421                         goto error_free_bh;
 422                 }
 423                 dr = (struct adfs_discrecord *)(b_data + ADFS_DR_OFFSET);
 424         } else {
 425                 if (!silent)
 426                         printk(KERN_ERR "VFS: Unsupported blocksize on dev "
 427                                 "%s.\n", sb->s_id);
 428                 goto error;
 429         }
 430
 431         /*
 432          * blocksize on this device should now be set to the ADFS log2secsize
 433          */
 434
 435         sb->s_magic             = ADFS_SUPER_MAGIC;
 436         asb->s_idlen            = dr->idlen;
 437         asb->s_map_size         = dr->nzones | (dr->nzones_high << 8);
 438         asb->s_map2blk          = dr->log2bpmb - dr->log2secsize;
 439         asb->s_size             = adfs_discsize(dr, sb->s_blocksize_bits);
 440         asb->s_version          = dr->format_version;
 441         asb->s_log2sharesize    = dr->log2sharesize;
 442
 443         asb->s_map = adfs_read_map(sb, dr);
 444         if (!asb->s_map)
 445                 goto error_free_bh;
 446
 447         brelse(bh);
 448
 449         /*
 450          * set up enough so that we can read an inode
 451          */
 452         sb->s_op = &adfs_sops;
 453
 454         dr = (struct adfs_discrecord *)(asb->s_map[0].dm_bh->b_data + 4);
 455
 456         root_obj.parent_id = root_obj.file_id = le32_to_cpu(dr->root);
 457         root_obj.name_len  = 0;
 458         root_obj.loadaddr  = 0;
 459         root_obj.execaddr  = 0;
 460         root_obj.size      = ADFS_NEWDIR_SIZE;
 461         root_obj.attr      = ADFS_NDA_DIRECTORY   | ADFS_NDA_OWNER_READ |
 462                              ADFS_NDA_OWNER_WRITE | ADFS_NDA_PUBLIC_READ;
 463
 464         /*
 465          * If this is a F+ disk with variable length directories,
 466          * get the root_size from the disc record.
 467          */
 468         if (asb->s_version) {
 469                 root_obj.size = le32_to_cpu(dr->root_size);
 470                 asb->s_dir     = &adfs_fplus_dir_ops;
 471                 asb->s_namelen = ADFS_FPLUS_NAME_LEN;
 472         } else {
 473                 asb->s_dir     = &adfs_f_dir_ops;
 474                 asb->s_namelen = ADFS_F_NAME_LEN;
 475         }
 476
 477         root = adfs_iget(sb, &root_obj);
 478         sb->s_root = d_alloc_root(root);
 479         if (!sb->s_root) {
 480                 int i;
 481                 iput(root);
 482                 for (i = 0; i < asb->s_map_size; i++)
 483                         brelse(asb->s_map[i].dm_bh);
 484                 kfree(asb->s_map);
 485                 adfs_error(sb, "get root inode failed\n");
 486                 goto error;
 487         } else
 488                 sb->s_root->d_op = &adfs_dentry_operations;
 489         return 0;
 490
 491 error_free_bh:
 492         brelse(bh);
 493 error:
 494         sb->s_fs_info = NULL;
 495         kfree(asb);
 496         return -EINVAL;
 497 }
 498
 499 static int adfs_get_sb(struct file_system_type *fs_type,
 500         int flags, const char *dev_name, void *data, struct vfsmount *mnt)
 501 {
 502         return get_sb_bdev(fs_type, flags, dev_name, data, adfs_fill_super,
 503                            mnt);
 504 }
 505
 506 static struct file_system_type adfs_fs_type = {
 507         .owner          = THIS_MODULE,
 508         .name           = "adfs",
 509         .get_sb         = adfs_get_sb,
 510         .kill_sb        = kill_block_super,
 511         .fs_flags       = FS_REQUIRES_DEV,
 512 };
 513
 514 static int __init init_adfs_fs(void)
 515 {
 516         int err = init_inodecache();
 517         if (err)
 518                 goto out1;
 519         err = register_filesystem(&adfs_fs_type);
 520         if (err)
 521                 goto out;
 522         return 0;
 523 out:
 524         destroy_inodecache();
 525 out1:
 526         return err;
 527 }
 528
 529 static void __exit exit_adfs_fs(void)
 530 {
 531         unregister_filesystem(&adfs_fs_type);
 532         destroy_inodecache();
 533 }
 534
 535 module_init(init_adfs_fs)
 536 module_exit(exit_adfs_fs)