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