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