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