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