fs/sysv/super.c

   1 /*
   2  *  linux/fs/sysv/inode.c
   3  *
   4  *  minix/inode.c
   5  *  Copyright (C) 1991, 1992  Linus Torvalds
   6  *
   7  *  xenix/inode.c
   8  *  Copyright (C) 1992  Doug Evans
   9  *
  10  *  coh/inode.c
  11  *  Copyright (C) 1993  Pascal Haible, Bruno Haible
  12  *
  13  *  sysv/inode.c
  14  *  Copyright (C) 1993  Paul B. Monday
  15  *
  16  *  sysv/inode.c
  17  *  Copyright (C) 1993  Bruno Haible
  18  *  Copyright (C) 1997, 1998  Krzysztof G. Baranowski
  19  *
  20  *  This file contains code for read/parsing the superblock.
  21  */
  22
  23 #include <linux/module.h>
  24 #include <linux/init.h>
  25 #include <linux/slab.h>
  26 #include <linux/buffer_head.h>
  27 #include "sysv.h"
  28
  29 /*
  30  * The following functions try to recognize specific filesystems.
  31  *
  32  * We recognize:
  33  * - Xenix FS by its magic number.
  34  * - SystemV FS by its magic number.
  35  * - Coherent FS by its funny fname/fpack field.
  36  * - SCO AFS by s_nfree == 0xffff
  37  * - V7 FS has no distinguishing features.
  38  *
  39  * We discriminate among SystemV4 and SystemV2 FS by the assumption that
  40  * the time stamp is not < 01-01-1980.
  41  */
  42
  43 enum {
  44         JAN_1_1980 = (10*365 + 2) * 24 * 60 * 60
  45 };
  46
  47 static void detected_xenix(struct sysv_sb_info *sbi, unsigned *max_links)
  48 {
  49         struct buffer_head *bh1 = sbi->s_bh1;
  50         struct buffer_head *bh2 = sbi->s_bh2;
  51         struct xenix_super_block * sbd1;
  52         struct xenix_super_block * sbd2;
  53
  54         if (bh1 != bh2)
  55                 sbd1 = sbd2 = (struct xenix_super_block *) bh1->b_data;
  56         else {
  57                 /* block size = 512, so bh1 != bh2 */
  58                 sbd1 = (struct xenix_super_block *) bh1->b_data;
  59                 sbd2 = (struct xenix_super_block *) (bh2->b_data - 512);
  60         }
  61
  62         *max_links = XENIX_LINK_MAX;
  63         sbi->s_fic_size = XENIX_NICINOD;
  64         sbi->s_flc_size = XENIX_NICFREE;
  65         sbi->s_sbd1 = (char *)sbd1;
  66         sbi->s_sbd2 = (char *)sbd2;
  67         sbi->s_sb_fic_count = &sbd1->s_ninode;
  68         sbi->s_sb_fic_inodes = &sbd1->s_inode[0];
  69         sbi->s_sb_total_free_inodes = &sbd2->s_tinode;
  70         sbi->s_bcache_count = &sbd1->s_nfree;
  71         sbi->s_bcache = &sbd1->s_free[0];
  72         sbi->s_free_blocks = &sbd2->s_tfree;
  73         sbi->s_sb_time = &sbd2->s_time;
  74         sbi->s_firstdatazone = fs16_to_cpu(sbi, sbd1->s_isize);
  75         sbi->s_nzones = fs32_to_cpu(sbi, sbd1->s_fsize);
  76 }
  77
  78 static void detected_sysv4(struct sysv_sb_info *sbi, unsigned *max_links)
  79 {
  80         struct sysv4_super_block * sbd;
  81         struct buffer_head *bh1 = sbi->s_bh1;
  82         struct buffer_head *bh2 = sbi->s_bh2;
  83
  84         if (bh1 == bh2)
  85                 sbd = (struct sysv4_super_block *) (bh1->b_data + BLOCK_SIZE/2);
  86         else
  87                 sbd = (struct sysv4_super_block *) bh2->b_data;
  88
  89         *max_links = SYSV_LINK_MAX;
  90         sbi->s_fic_size = SYSV_NICINOD;
  91         sbi->s_flc_size = SYSV_NICFREE;
  92         sbi->s_sbd1 = (char *)sbd;
  93         sbi->s_sbd2 = (char *)sbd;
  94         sbi->s_sb_fic_count = &sbd->s_ninode;
  95         sbi->s_sb_fic_inodes = &sbd->s_inode[0];
  96         sbi->s_sb_total_free_inodes = &sbd->s_tinode;
  97         sbi->s_bcache_count = &sbd->s_nfree;
  98         sbi->s_bcache = &sbd->s_free[0];
  99         sbi->s_free_blocks = &sbd->s_tfree;
 100         sbi->s_sb_time = &sbd->s_time;
 101         sbi->s_sb_state = &sbd->s_state;
 102         sbi->s_firstdatazone = fs16_to_cpu(sbi, sbd->s_isize);
 103         sbi->s_nzones = fs32_to_cpu(sbi, sbd->s_fsize);
 104 }
 105
 106 static void detected_sysv2(struct sysv_sb_info *sbi, unsigned *max_links)
 107 {
 108         struct sysv2_super_block *sbd;
 109         struct buffer_head *bh1 = sbi->s_bh1;
 110         struct buffer_head *bh2 = sbi->s_bh2;
 111
 112         if (bh1 == bh2)
 113                 sbd = (struct sysv2_super_block *) (bh1->b_data + BLOCK_SIZE/2);
 114         else
 115                 sbd = (struct sysv2_super_block *) bh2->b_data;
 116
 117         *max_links = SYSV_LINK_MAX;
 118         sbi->s_fic_size = SYSV_NICINOD;
 119         sbi->s_flc_size = SYSV_NICFREE;
 120         sbi->s_sbd1 = (char *)sbd;
 121         sbi->s_sbd2 = (char *)sbd;
 122         sbi->s_sb_fic_count = &sbd->s_ninode;
 123         sbi->s_sb_fic_inodes = &sbd->s_inode[0];
 124         sbi->s_sb_total_free_inodes = &sbd->s_tinode;
 125         sbi->s_bcache_count = &sbd->s_nfree;
 126         sbi->s_bcache = &sbd->s_free[0];
 127         sbi->s_free_blocks = &sbd->s_tfree;
 128         sbi->s_sb_time = &sbd->s_time;
 129         sbi->s_sb_state = &sbd->s_state;
 130         sbi->s_firstdatazone = fs16_to_cpu(sbi, sbd->s_isize);
 131         sbi->s_nzones = fs32_to_cpu(sbi, sbd->s_fsize);
 132 }
 133
 134 static void detected_coherent(struct sysv_sb_info *sbi, unsigned *max_links)
 135 {
 136         struct coh_super_block * sbd;
 137         struct buffer_head *bh1 = sbi->s_bh1;
 138
 139         sbd = (struct coh_super_block *) bh1->b_data;
 140
 141         *max_links = COH_LINK_MAX;
 142         sbi->s_fic_size = COH_NICINOD;
 143         sbi->s_flc_size = COH_NICFREE;
 144         sbi->s_sbd1 = (char *)sbd;
 145         sbi->s_sbd2 = (char *)sbd;
 146         sbi->s_sb_fic_count = &sbd->s_ninode;
 147         sbi->s_sb_fic_inodes = &sbd->s_inode[0];
 148         sbi->s_sb_total_free_inodes = &sbd->s_tinode;
 149         sbi->s_bcache_count = &sbd->s_nfree;
 150         sbi->s_bcache = &sbd->s_free[0];
 151         sbi->s_free_blocks = &sbd->s_tfree;
 152         sbi->s_sb_time = &sbd->s_time;
 153         sbi->s_firstdatazone = fs16_to_cpu(sbi, sbd->s_isize);
 154         sbi->s_nzones = fs32_to_cpu(sbi, sbd->s_fsize);
 155 }
 156
 157 static void detected_v7(struct sysv_sb_info *sbi, unsigned *max_links)
 158 {
 159         struct buffer_head *bh2 = sbi->s_bh2;
 160         struct v7_super_block *sbd = (struct v7_super_block *)bh2->b_data;
 161
 162         *max_links = V7_LINK_MAX;
 163         sbi->s_fic_size = V7_NICINOD;
 164         sbi->s_flc_size = V7_NICFREE;
 165         sbi->s_sbd1 = (char *)sbd;
 166         sbi->s_sbd2 = (char *)sbd;
 167         sbi->s_sb_fic_count = &sbd->s_ninode;
 168         sbi->s_sb_fic_inodes = &sbd->s_inode[0];
 169         sbi->s_sb_total_free_inodes = &sbd->s_tinode;
 170         sbi->s_bcache_count = &sbd->s_nfree;
 171         sbi->s_bcache = &sbd->s_free[0];
 172         sbi->s_free_blocks = &sbd->s_tfree;
 173         sbi->s_sb_time = &sbd->s_time;
 174         sbi->s_firstdatazone = fs16_to_cpu(sbi, sbd->s_isize);
 175         sbi->s_nzones = fs32_to_cpu(sbi, sbd->s_fsize);
 176 }
 177
 178 static int detect_xenix(struct sysv_sb_info *sbi, struct buffer_head *bh)
 179 {
 180         struct xenix_super_block *sbd = (struct xenix_super_block *)bh->b_data;
 181         if (*(__le32 *)&sbd->s_magic == cpu_to_le32(0x2b5544))
 182                 sbi->s_bytesex = BYTESEX_LE;
 183         else if (*(__be32 *)&sbd->s_magic == cpu_to_be32(0x2b5544))
 184                 sbi->s_bytesex = BYTESEX_BE;
 185         else
 186                 return 0;
 187         switch (fs32_to_cpu(sbi, sbd->s_type)) {
 188         case 1:
 189                 sbi->s_type = FSTYPE_XENIX;
 190                 return 1;
 191         case 2:
 192                 sbi->s_type = FSTYPE_XENIX;
 193                 return 2;
 194         default:
 195                 return 0;
 196         }
 197 }
 198
 199 static int detect_sysv(struct sysv_sb_info *sbi, struct buffer_head *bh)
 200 {
 201         struct super_block *sb = sbi->s_sb;
 202         /* All relevant fields are at the same offsets in R2 and R4 */
 203         struct sysv4_super_block * sbd;
 204         u32 type;
 205
 206         sbd = (struct sysv4_super_block *) (bh->b_data + BLOCK_SIZE/2);
 207         if (*(__le32 *)&sbd->s_magic == cpu_to_le32(0xfd187e20))
 208                 sbi->s_bytesex = BYTESEX_LE;
 209         else if (*(__be32 *)&sbd->s_magic == cpu_to_be32(0xfd187e20))
 210                 sbi->s_bytesex = BYTESEX_BE;
 211         else
 212                 return 0;
 213
 214         type = fs32_to_cpu(sbi, sbd->s_type);
 215
 216         if (fs16_to_cpu(sbi, sbd->s_nfree) == 0xffff) {
 217                 sbi->s_type = FSTYPE_AFS;
 218                 sbi->s_forced_ro = 1;
 219                 if (!sb_rdonly(sb)) {
 220                         printk("SysV FS: SCO EAFS on %s detected, "
 221                                 "forcing read-only mode.\n",
 222                                 sb->s_id);
 223                 }
 224                 return type;
 225         }
 226
 227         if (fs32_to_cpu(sbi, sbd->s_time) < JAN_1_1980) {
 228                 /* this is likely to happen on SystemV2 FS */
 229                 if (type > 3 || type < 1)
 230                         return 0;
 231                 sbi->s_type = FSTYPE_SYSV2;
 232                 return type;
 233         }
 234         if ((type > 3 || type < 1) && (type > 0x30 || type < 0x10))
 235                 return 0;
 236
 237         /* On Interactive Unix (ISC) Version 4.0/3.x s_type field = 0x10,
 238            0x20 or 0x30 indicates that symbolic links and the 14-character
 239            filename limit is gone. Due to lack of information about this
 240            feature read-only mode seems to be a reasonable approach... -KGB */
 241
 242         if (type >= 0x10) {
 243                 printk("SysV FS: can't handle long file names on %s, "
 244                        "forcing read-only mode.\n", sb->s_id);
 245                 sbi->s_forced_ro = 1;
 246         }
 247
 248         sbi->s_type = FSTYPE_SYSV4;
 249         return type >= 0x10 ? type >> 4 : type;
 250 }
 251
 252 static int detect_coherent(struct sysv_sb_info *sbi, struct buffer_head *bh)
 253 {
 254         struct coh_super_block * sbd;
 255
 256         sbd = (struct coh_super_block *) (bh->b_data + BLOCK_SIZE/2);
 257         if ((memcmp(sbd->s_fname,"noname",6) && memcmp(sbd->s_fname,"xxxxx ",6))
 258             || (memcmp(sbd->s_fpack,"nopack",6) && memcmp(sbd->s_fpack,"xxxxx\n",6)))
 259                 return 0;
 260         sbi->s_bytesex = BYTESEX_PDP;
 261         sbi->s_type = FSTYPE_COH;
 262         return 1;
 263 }
 264
 265 static int detect_sysv_odd(struct sysv_sb_info *sbi, struct buffer_head *bh)
 266 {
 267         int size = detect_sysv(sbi, bh);
 268
 269         return size>2 ? 0 : size;
 270 }
 271
 272 static struct {
 273         int block;
 274         int (*test)(struct sysv_sb_info *, struct buffer_head *);
 275 } flavours[] = {
 276         {1, detect_xenix},
 277         {0, detect_sysv},
 278         {0, detect_coherent},
 279         {9, detect_sysv_odd},
 280         {15,detect_sysv_odd},
 281         {18,detect_sysv},
 282 };
 283
 284 static char *flavour_names[] = {
 285         [FSTYPE_XENIX]  = "Xenix",
 286         [FSTYPE_SYSV4]  = "SystemV",
 287         [FSTYPE_SYSV2]  = "SystemV Release 2",
 288         [FSTYPE_COH]    = "Coherent",
 289         [FSTYPE_V7]     = "V7",
 290         [FSTYPE_AFS]    = "AFS",
 291 };
 292
 293 static void (*flavour_setup[])(struct sysv_sb_info *, unsigned *) = {
 294         [FSTYPE_XENIX]  = detected_xenix,
 295         [FSTYPE_SYSV4]  = detected_sysv4,
 296         [FSTYPE_SYSV2]  = detected_sysv2,
 297         [FSTYPE_COH]    = detected_coherent,
 298         [FSTYPE_V7]     = detected_v7,
 299         [FSTYPE_AFS]    = detected_sysv4,
 300 };
 301
 302 static int complete_read_super(struct super_block *sb, int silent, int size)
 303 {
 304         struct sysv_sb_info *sbi = SYSV_SB(sb);
 305         struct inode *root_inode;
 306         char *found = flavour_names[sbi->s_type];
 307         u_char n_bits = size+8;
 308         int bsize = 1 << n_bits;
 309         int bsize_4 = bsize >> 2;
 310
 311         sbi->s_firstinodezone = 2;
 312
 313         flavour_setup[sbi->s_type](sbi, &sb->s_max_links);
 314
 315         sbi->s_ndatazones = sbi->s_nzones - sbi->s_firstdatazone;
 316         sbi->s_inodes_per_block = bsize >> 6;
 317         sbi->s_inodes_per_block_1 = (bsize >> 6)-1;
 318         sbi->s_inodes_per_block_bits = n_bits-6;
 319         sbi->s_ind_per_block = bsize_4;
 320         sbi->s_ind_per_block_2 = bsize_4*bsize_4;
 321         sbi->s_toobig_block = 10 + bsize_4 * (1 + bsize_4 * (1 + bsize_4));
 322         sbi->s_ind_per_block_bits = n_bits-2;
 323
 324         sbi->s_ninodes = (sbi->s_firstdatazone - sbi->s_firstinodezone)
 325                 << sbi->s_inodes_per_block_bits;
 326
 327         if (!silent)
 328                 printk("VFS: Found a %s FS (block size = %ld) on device %s\n",
 329                        found, sb->s_blocksize, sb->s_id);
 330
 331         sb->s_magic = SYSV_MAGIC_BASE + sbi->s_type;
 332         /* set up enough so that it can read an inode */
 333         sb->s_op = &sysv_sops;
 334         if (sbi->s_forced_ro)
 335                 sb->s_flags |= SB_RDONLY;
 336         root_inode = sysv_iget(sb, SYSV_ROOT_INO);
 337         if (IS_ERR(root_inode)) {
 338                 printk("SysV FS: get root inode failed\n");
 339                 return 0;
 340         }
 341         sb->s_root = d_make_root(root_inode);
 342         if (!sb->s_root) {
 343                 printk("SysV FS: get root dentry failed\n");
 344                 return 0;
 345         }
 346         return 1;
 347 }
 348
 349 static int sysv_fill_super(struct super_block *sb, void *data, int silent)
 350 {
 351         struct buffer_head *bh1, *bh = NULL;
 352         struct sysv_sb_info *sbi;
 353         unsigned long blocknr;
 354         int size = 0, i;
 355
 356         BUILD_BUG_ON(1024 != sizeof (struct xenix_super_block));
 357         BUILD_BUG_ON(512 != sizeof (struct sysv4_super_block));
 358         BUILD_BUG_ON(512 != sizeof (struct sysv2_super_block));
 359         BUILD_BUG_ON(500 != sizeof (struct coh_super_block));
 360         BUILD_BUG_ON(64 != sizeof (struct sysv_inode));
 361
 362         sbi = kzalloc(sizeof(struct sysv_sb_info), GFP_KERNEL);
 363         if (!sbi)
 364                 return -ENOMEM;
 365
 366         sbi->s_sb = sb;
 367         sbi->s_block_base = 0;
 368         mutex_init(&sbi->s_lock);
 369         sb->s_fs_info = sbi;
 370
 371         sb_set_blocksize(sb, BLOCK_SIZE);
 372
 373         for (i = 0; i < ARRAY_SIZE(flavours) && !size; i++) {
 374                 brelse(bh);
 375                 bh = sb_bread(sb, flavours[i].block);
 376                 if (!bh)
 377                         continue;
 378                 size = flavours[i].test(SYSV_SB(sb), bh);
 379         }
 380
 381         if (!size)
 382                 goto Eunknown;
 383
 384         switch (size) {
 385                 case 1:
 386                         blocknr = bh->b_blocknr << 1;
 387                         brelse(bh);
 388                         sb_set_blocksize(sb, 512);
 389                         bh1 = sb_bread(sb, blocknr);
 390                         bh = sb_bread(sb, blocknr + 1);
 391                         break;
 392                 case 2:
 393                         bh1 = bh;
 394                         break;
 395                 case 3:
 396                         blocknr = bh->b_blocknr >> 1;
 397                         brelse(bh);
 398                         sb_set_blocksize(sb, 2048);
 399                         bh1 = bh = sb_bread(sb, blocknr);
 400                         break;
 401                 default:
 402                         goto Ebadsize;
 403         }
 404
 405         if (bh && bh1) {
 406                 sbi->s_bh1 = bh1;
 407                 sbi->s_bh2 = bh;
 408                 if (complete_read_super(sb, silent, size))
 409                         return 0;
 410         }
 411
 412         brelse(bh1);
 413         brelse(bh);
 414         sb_set_blocksize(sb, BLOCK_SIZE);
 415         printk("oldfs: cannot read superblock\n");
 416 failed:
 417         kfree(sbi);
 418         return -EINVAL;
 419
 420 Eunknown:
 421         brelse(bh);
 422         if (!silent)
 423                 printk("VFS: unable to find oldfs superblock on device %s\n",
 424                         sb->s_id);
 425         goto failed;
 426 Ebadsize:
 427         brelse(bh);
 428         if (!silent)
 429                 printk("VFS: oldfs: unsupported block size (%dKb)\n",
 430                         1<<(size-2));
 431         goto failed;
 432 }
 433
 434 static int v7_sanity_check(struct super_block *sb, struct buffer_head *bh)
 435 {
 436         struct v7_super_block *v7sb;
 437         struct sysv_inode *v7i;
 438         struct buffer_head *bh2;
 439         struct sysv_sb_info *sbi;
 440
 441         sbi = sb->s_fs_info;
 442
 443         /* plausibility check on superblock */
 444         v7sb = (struct v7_super_block *) bh->b_data;
 445         if (fs16_to_cpu(sbi, v7sb->s_nfree) > V7_NICFREE ||
 446             fs16_to_cpu(sbi, v7sb->s_ninode) > V7_NICINOD ||
 447             fs32_to_cpu(sbi, v7sb->s_fsize) > V7_MAXSIZE)
 448                 return 0;
 449
 450         /* plausibility check on root inode: it is a directory,
 451            with a nonzero size that is a multiple of 16 */
 452         bh2 = sb_bread(sb, 2);
 453         if (bh2 == NULL)
 454                 return 0;
 455
 456         v7i = (struct sysv_inode *)(bh2->b_data + 64);
 457         if ((fs16_to_cpu(sbi, v7i->i_mode) & ~0777) != S_IFDIR ||
 458             (fs32_to_cpu(sbi, v7i->i_size) == 0) ||
 459             (fs32_to_cpu(sbi, v7i->i_size) & 017) ||
 460             (fs32_to_cpu(sbi, v7i->i_size) > V7_NFILES *
 461              sizeof(struct sysv_dir_entry))) {
 462                 brelse(bh2);
 463                 return 0;
 464         }
 465
 466         brelse(bh2);
 467         return 1;
 468 }
 469
 470 static int v7_fill_super(struct super_block *sb, void *data, int silent)
 471 {
 472         struct sysv_sb_info *sbi;
 473         struct buffer_head *bh;
 474
 475         if (440 != sizeof (struct v7_super_block))
 476                 panic("V7 FS: bad super-block size");
 477         if (64 != sizeof (struct sysv_inode))
 478                 panic("sysv fs: bad i-node size");
 479
 480         sbi = kzalloc(sizeof(struct sysv_sb_info), GFP_KERNEL);
 481         if (!sbi)
 482                 return -ENOMEM;
 483
 484         sbi->s_sb = sb;
 485         sbi->s_block_base = 0;
 486         sbi->s_type = FSTYPE_V7;
 487         mutex_init(&sbi->s_lock);
 488         sb->s_fs_info = sbi;
 489
 490         sb_set_blocksize(sb, 512);
 491
 492         if ((bh = sb_bread(sb, 1)) == NULL) {
 493                 if (!silent)
 494                         printk("VFS: unable to read V7 FS superblock on "
 495                                "device %s.\n", sb->s_id);
 496                 goto failed;
 497         }
 498
 499         /* Try PDP-11 UNIX */
 500         sbi->s_bytesex = BYTESEX_PDP;
 501         if (v7_sanity_check(sb, bh))
 502                 goto detected;
 503
 504         /* Try PC/IX, v7/x86 */
 505         sbi->s_bytesex = BYTESEX_LE;
 506         if (v7_sanity_check(sb, bh))
 507                 goto detected;
 508
 509         goto failed;
 510
 511 detected:
 512         sbi->s_bh1 = bh;
 513         sbi->s_bh2 = bh;
 514         if (complete_read_super(sb, silent, 1))
 515                 return 0;
 516
 517 failed:
 518         printk(KERN_ERR "VFS: could not find a valid V7 on %s.\n",
 519                 sb->s_id);
 520         brelse(bh);
 521         kfree(sbi);
 522         return -EINVAL;
 523 }
 524
 525 /* Every kernel module contains stuff like this. */
 526
 527 static struct dentry *sysv_mount(struct file_system_type *fs_type,
 528         int flags, const char *dev_name, void *data)
 529 {
 530         return mount_bdev(fs_type, flags, dev_name, data, sysv_fill_super);
 531 }
 532
 533 static struct dentry *v7_mount(struct file_system_type *fs_type,
 534         int flags, const char *dev_name, void *data)
 535 {
 536         return mount_bdev(fs_type, flags, dev_name, data, v7_fill_super);
 537 }
 538
 539 static struct file_system_type sysv_fs_type = {
 540         .owner          = THIS_MODULE,
 541         .name           = "sysv",
 542         .mount          = sysv_mount,
 543         .kill_sb        = kill_block_super,
 544         .fs_flags       = FS_REQUIRES_DEV,
 545 };
 546 MODULE_ALIAS_FS("sysv");
 547
 548 static struct file_system_type v7_fs_type = {
 549         .owner          = THIS_MODULE,
 550         .name           = "v7",
 551         .mount          = v7_mount,
 552         .kill_sb        = kill_block_super,
 553         .fs_flags       = FS_REQUIRES_DEV,
 554 };
 555 MODULE_ALIAS_FS("v7");
 556 MODULE_ALIAS("v7");
 557
 558 static int __init init_sysv_fs(void)
 559 {
 560         int error;
 561
 562         error = sysv_init_icache();
 563         if (error)
 564                 goto out;
 565         error = register_filesystem(&sysv_fs_type);
 566         if (error)
 567                 goto destroy_icache;
 568         error = register_filesystem(&v7_fs_type);
 569         if (error)
 570                 goto unregister;
 571         return 0;
 572
 573 unregister:
 574         unregister_filesystem(&sysv_fs_type);
 575 destroy_icache:
 576         sysv_destroy_icache();
 577 out:
 578         return error;
 579 }
 580
 581 static void __exit exit_sysv_fs(void)
 582 {
 583         unregister_filesystem(&sysv_fs_type);
 584         unregister_filesystem(&v7_fs_type);
 585         sysv_destroy_icache();
 586 }
 587
 588 module_init(init_sysv_fs)
 589 module_exit(exit_sysv_fs)
 590 MODULE_LICENSE("GPL");