fs/sysv/super.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  *  linux/fs/sysv/inode.c
   4  *
   5  *  minix/inode.c
   6  *  Copyright (C) 1991, 1992  Linus Torvalds
   7  *
   8  *  xenix/inode.c
   9  *  Copyright (C) 1992  Doug Evans
  10  *
  11  *  coh/inode.c
  12  *  Copyright (C) 1993  Pascal Haible, Bruno Haible
  13  *
  14  *  sysv/inode.c
  15  *  Copyright (C) 1993  Paul B. Monday
  16  *
  17  *  sysv/inode.c
  18  *  Copyright (C) 1993  Bruno Haible
  19  *  Copyright (C) 1997, 1998  Krzysztof G. Baranowski
  20  *
  21  *  This file contains code for read/parsing the superblock.
  22  */
  23
  24 #include <linux/module.h>
  25 #include <linux/init.h>
  26 #include <linux/slab.h>
  27 #include <linux/buffer_head.h>
  28 #include "sysv.h"
  29
  30 /*
  31  * The following functions try to recognize specific filesystems.
  32  *
  33  * We recognize:
  34  * - Xenix FS by its magic number.
  35  * - SystemV FS by its magic number.
  36  * - Coherent FS by its funny fname/fpack field.
  37  * - SCO AFS by s_nfree == 0xffff
  38  * - V7 FS has no distinguishing features.
  39  *
  40  * We discriminate among SystemV4 and SystemV2 FS by the assumption that
  41  * the time stamp is not < 01-01-1980.
  42  */
  43
  44 enum {
  45         JAN_1_1980 = (10*365 + 2) * 24 * 60 * 60
  46 };
  47
  48 static void detected_xenix(struct sysv_sb_info *sbi, unsigned *max_links)
  49 {
  50         struct buffer_head *bh1 = sbi->s_bh1;
  51         struct buffer_head *bh2 = sbi->s_bh2;
  52         struct xenix_super_block * sbd1;
  53         struct xenix_super_block * sbd2;
  54
  55         if (bh1 != bh2)
  56                 sbd1 = sbd2 = (struct xenix_super_block *) bh1->b_data;
  57         else {
  58                 /* block size = 512, so bh1 != bh2 */
  59                 sbd1 = (struct xenix_super_block *) bh1->b_data;
  60                 sbd2 = (struct xenix_super_block *) (bh2->b_data - 512);
  61         }
  62
  63         *max_links = XENIX_LINK_MAX;
  64         sbi->s_fic_size = XENIX_NICINOD;
  65         sbi->s_flc_size = XENIX_NICFREE;
  66         sbi->s_sbd1 = (char *)sbd1;
  67         sbi->s_sbd2 = (char *)sbd2;
  68         sbi->s_sb_fic_count = &sbd1->s_ninode;
  69         sbi->s_sb_fic_inodes = &sbd1->s_inode[0];
  70         sbi->s_sb_total_free_inodes = &sbd2->s_tinode;
  71         sbi->s_bcache_count = &sbd1->s_nfree;
  72         sbi->s_bcache = &sbd1->s_free[0];
  73         sbi->s_free_blocks = &sbd2->s_tfree;
  74         sbi->s_sb_time = &sbd2->s_time;
  75         sbi->s_firstdatazone = fs16_to_cpu(sbi, sbd1->s_isize);
  76         sbi->s_nzones = fs32_to_cpu(sbi, sbd1->s_fsize);
  77 }
  78
  79 static void detected_sysv4(struct sysv_sb_info *sbi, unsigned *max_links)
  80 {
  81         struct sysv4_super_block * sbd;
  82         struct buffer_head *bh1 = sbi->s_bh1;
  83         struct buffer_head *bh2 = sbi->s_bh2;
  84
  85         if (bh1 == bh2)
  86                 sbd = (struct sysv4_super_block *) (bh1->b_data + BLOCK_SIZE/2);
  87         else
  88                 sbd = (struct sysv4_super_block *) bh2->b_data;
  89
  90         *max_links = SYSV_LINK_MAX;
  91         sbi->s_fic_size = SYSV_NICINOD;
  92         sbi->s_flc_size = SYSV_NICFREE;
  93         sbi->s_sbd1 = (char *)sbd;
  94         sbi->s_sbd2 = (char *)sbd;
  95         sbi->s_sb_fic_count = &sbd->s_ninode;
  96         sbi->s_sb_fic_inodes = &sbd->s_inode[0];
  97         sbi->s_sb_total_free_inodes = &sbd->s_tinode;
  98         sbi->s_bcache_count = &sbd->s_nfree;
  99         sbi->s_bcache = &sbd->s_free[0];
 100         sbi->s_free_blocks = &sbd->s_tfree;
 101         sbi->s_sb_time = &sbd->s_time;
 102         sbi->s_sb_state = &sbd->s_state;
 103         sbi->s_firstdatazone = fs16_to_cpu(sbi, sbd->s_isize);
 104         sbi->s_nzones = fs32_to_cpu(sbi, sbd->s_fsize);
 105 }
 106
 107 static void detected_sysv2(struct sysv_sb_info *sbi, unsigned *max_links)
 108 {
 109         struct sysv2_super_block *sbd;
 110         struct buffer_head *bh1 = sbi->s_bh1;
 111         struct buffer_head *bh2 = sbi->s_bh2;
 112
 113         if (bh1 == bh2)
 114                 sbd = (struct sysv2_super_block *) (bh1->b_data + BLOCK_SIZE/2);
 115         else
 116                 sbd = (struct sysv2_super_block *) bh2->b_data;
 117
 118         *max_links = SYSV_LINK_MAX;
 119         sbi->s_fic_size = SYSV_NICINOD;
 120         sbi->s_flc_size = SYSV_NICFREE;
 121         sbi->s_sbd1 = (char *)sbd;
 122         sbi->s_sbd2 = (char *)sbd;
 123         sbi->s_sb_fic_count = &sbd->s_ninode;
 124         sbi->s_sb_fic_inodes = &sbd->s_inode[0];
 125         sbi->s_sb_total_free_inodes = &sbd->s_tinode;
 126         sbi->s_bcache_count = &sbd->s_nfree;
 127         sbi->s_bcache = &sbd->s_free[0];
 128         sbi->s_free_blocks = &sbd->s_tfree;
 129         sbi->s_sb_time = &sbd->s_time;
 130         sbi->s_sb_state = &sbd->s_state;
 131         sbi->s_firstdatazone = fs16_to_cpu(sbi, sbd->s_isize);
 132         sbi->s_nzones = fs32_to_cpu(sbi, sbd->s_fsize);
 133 }
 134
 135 static void detected_coherent(struct sysv_sb_info *sbi, unsigned *max_links)
 136 {
 137         struct coh_super_block * sbd;
 138         struct buffer_head *bh1 = sbi->s_bh1;
 139
 140         sbd = (struct coh_super_block *) bh1->b_data;
 141
 142         *max_links = COH_LINK_MAX;
 143         sbi->s_fic_size = COH_NICINOD;
 144         sbi->s_flc_size = COH_NICFREE;
 145         sbi->s_sbd1 = (char *)sbd;
 146         sbi->s_sbd2 = (char *)sbd;
 147         sbi->s_sb_fic_count = &sbd->s_ninode;
 148         sbi->s_sb_fic_inodes = &sbd->s_inode[0];
 149         sbi->s_sb_total_free_inodes = &sbd->s_tinode;
 150         sbi->s_bcache_count = &sbd->s_nfree;
 151         sbi->s_bcache = &sbd->s_free[0];
 152         sbi->s_free_blocks = &sbd->s_tfree;
 153         sbi->s_sb_time = &sbd->s_time;
 154         sbi->s_firstdatazone = fs16_to_cpu(sbi, sbd->s_isize);
 155         sbi->s_nzones = fs32_to_cpu(sbi, sbd->s_fsize);
 156 }
 157
 158 static void detected_v7(struct sysv_sb_info *sbi, unsigned *max_links)
 159 {
 160         struct buffer_head *bh2 = sbi->s_bh2;
 161         struct v7_super_block *sbd = (struct v7_super_block *)bh2->b_data;
 162
 163         *max_links = V7_LINK_MAX;
 164         sbi->s_fic_size = V7_NICINOD;
 165         sbi->s_flc_size = V7_NICFREE;
 166         sbi->s_sbd1 = (char *)sbd;
 167         sbi->s_sbd2 = (char *)sbd;
 168         sbi->s_sb_fic_count = &sbd->s_ninode;
 169         sbi->s_sb_fic_inodes = &sbd->s_inode[0];
 170         sbi->s_sb_total_free_inodes = &sbd->s_tinode;
 171         sbi->s_bcache_count = &sbd->s_nfree;
 172         sbi->s_bcache = &sbd->s_free[0];
 173         sbi->s_free_blocks = &sbd->s_tfree;
 174         sbi->s_sb_time = &sbd->s_time;
 175         sbi->s_firstdatazone = fs16_to_cpu(sbi, sbd->s_isize);
 176         sbi->s_nzones = fs32_to_cpu(sbi, sbd->s_fsize);
 177 }
 178
 179 static int detect_xenix(struct sysv_sb_info *sbi, struct buffer_head *bh)
 180 {
 181         struct xenix_super_block *sbd = (struct xenix_super_block *)bh->b_data;
 182         if (*(__le32 *)&sbd->s_magic == cpu_to_le32(0x2b5544))
 183                 sbi->s_bytesex = BYTESEX_LE;
 184         else if (*(__be32 *)&sbd->s_magic == cpu_to_be32(0x2b5544))
 185                 sbi->s_bytesex = BYTESEX_BE;
 186         else
 187                 return 0;
 188         switch (fs32_to_cpu(sbi, sbd->s_type)) {
 189         case 1:
 190                 sbi->s_type = FSTYPE_XENIX;
 191                 return 1;
 192         case 2:
 193                 sbi->s_type = FSTYPE_XENIX;
 194                 return 2;
 195         default:
 196                 return 0;
 197         }
 198 }
 199
 200 static int detect_sysv(struct sysv_sb_info *sbi, struct buffer_head *bh)
 201 {
 202         struct super_block *sb = sbi->s_sb;
 203         /* All relevant fields are at the same offsets in R2 and R4 */
 204         struct sysv4_super_block * sbd;
 205         u32 type;
 206
 207         sbd = (struct sysv4_super_block *) (bh->b_data + BLOCK_SIZE/2);
 208         if (*(__le32 *)&sbd->s_magic == cpu_to_le32(0xfd187e20))
 209                 sbi->s_bytesex = BYTESEX_LE;
 210         else if (*(__be32 *)&sbd->s_magic == cpu_to_be32(0xfd187e20))
 211                 sbi->s_bytesex = BYTESEX_BE;
 212         else
 213                 return 0;
 214
 215         type = fs32_to_cpu(sbi, sbd->s_type);
 216
 217         if (fs16_to_cpu(sbi, sbd->s_nfree) == 0xffff) {
 218                 sbi->s_type = FSTYPE_AFS;
 219                 sbi->s_forced_ro = 1;
 220                 if (!sb_rdonly(sb)) {
 221                         printk("SysV FS: SCO EAFS on %s detected, "
 222                                 "forcing read-only mode.\n",
 223                                 sb->s_id);
 224                 }
 225                 return type;
 226         }
 227
 228         if (fs32_to_cpu(sbi, sbd->s_time) < JAN_1_1980) {
 229                 /* this is likely to happen on SystemV2 FS */
 230                 if (type > 3 || type < 1)
 231                         return 0;
 232                 sbi->s_type = FSTYPE_SYSV2;
 233                 return type;
 234         }
 235         if ((type > 3 || type < 1) && (type > 0x30 || type < 0x10))
 236                 return 0;
 237
 238         /* On Interactive Unix (ISC) Version 4.0/3.x s_type field = 0x10,
 239            0x20 or 0x30 indicates that symbolic links and the 14-character
 240            filename limit is gone. Due to lack of information about this
 241            feature read-only mode seems to be a reasonable approach... -KGB */
 242
 243         if (type >= 0x10) {
 244                 printk("SysV FS: can't handle long file names on %s, "
 245                        "forcing read-only mode.\n", sb->s_id);
 246                 sbi->s_forced_ro = 1;
 247         }
 248
 249         sbi->s_type = FSTYPE_SYSV4;
 250         return type >= 0x10 ? type >> 4 : type;
 251 }
 252
 253 static int detect_coherent(struct sysv_sb_info *sbi, struct buffer_head *bh)
 254 {
 255         struct coh_super_block * sbd;
 256
 257         sbd = (struct coh_super_block *) (bh->b_data + BLOCK_SIZE/2);
 258         if ((memcmp(sbd->s_fname,"noname",6) && memcmp(sbd->s_fname,"xxxxx ",6))
 259             || (memcmp(sbd->s_fpack,"nopack",6) && memcmp(sbd->s_fpack,"xxxxx\n",6)))
 260                 return 0;
 261         sbi->s_bytesex = BYTESEX_PDP;
 262         sbi->s_type = FSTYPE_COH;
 263         return 1;
 264 }
 265
 266 static int detect_sysv_odd(struct sysv_sb_info *sbi, struct buffer_head *bh)
 267 {
 268         int size = detect_sysv(sbi, bh);
 269
 270         return size>2 ? 0 : size;
 271 }
 272
 273 static struct {
 274         int block;
 275         int (*test)(struct sysv_sb_info *, struct buffer_head *);
 276 } flavours[] = {
 277         {1, detect_xenix},
 278         {0, detect_sysv},
 279         {0, detect_coherent},
 280         {9, detect_sysv_odd},
 281         {15,detect_sysv_odd},
 282         {18,detect_sysv},
 283 };
 284
 285 static char *flavour_names[] = {
 286         [FSTYPE_XENIX]  = "Xenix",
 287         [FSTYPE_SYSV4]  = "SystemV",
 288         [FSTYPE_SYSV2]  = "SystemV Release 2",
 289         [FSTYPE_COH]    = "Coherent",
 290         [FSTYPE_V7]     = "V7",
 291         [FSTYPE_AFS]    = "AFS",
 292 };
 293
 294 static void (*flavour_setup[])(struct sysv_sb_info *, unsigned *) = {
 295         [FSTYPE_XENIX]  = detected_xenix,
 296         [FSTYPE_SYSV4]  = detected_sysv4,
 297         [FSTYPE_SYSV2]  = detected_sysv2,
 298         [FSTYPE_COH]    = detected_coherent,
 299         [FSTYPE_V7]     = detected_v7,
 300         [FSTYPE_AFS]    = detected_sysv4,
 301 };
 302
 303 static int complete_read_super(struct super_block *sb, int silent, int size)
 304 {
 305         struct sysv_sb_info *sbi = SYSV_SB(sb);
 306         struct inode *root_inode;
 307         char *found = flavour_names[sbi->s_type];
 308         u_char n_bits = size+8;
 309         int bsize = 1 << n_bits;
 310         int bsize_4 = bsize >> 2;
 311
 312         sbi->s_firstinodezone = 2;
 313
 314         flavour_setup[sbi->s_type](sbi, &sb->s_max_links);
 315
 316         sbi->s_ndatazones = sbi->s_nzones - sbi->s_firstdatazone;
 317         sbi->s_inodes_per_block = bsize >> 6;
 318         sbi->s_inodes_per_block_1 = (bsize >> 6)-1;
 319         sbi->s_inodes_per_block_bits = n_bits-6;
 320         sbi->s_ind_per_block = bsize_4;
 321         sbi->s_ind_per_block_2 = bsize_4*bsize_4;
 322         sbi->s_toobig_block = 10 + bsize_4 * (1 + bsize_4 * (1 + bsize_4));
 323         sbi->s_ind_per_block_bits = n_bits-2;
 324
 325         sbi->s_ninodes = (sbi->s_firstdatazone - sbi->s_firstinodezone)
 326                 << sbi->s_inodes_per_block_bits;
 327
 328         if (!silent)
 329                 printk("VFS: Found a %s FS (block size = %ld) on device %s\n",
 330                        found, sb->s_blocksize, sb->s_id);
 331
 332         sb->s_magic = SYSV_MAGIC_BASE + sbi->s_type;
 333         /* set up enough so that it can read an inode */
 334         sb->s_op = &sysv_sops;
 335         if (sbi->s_forced_ro)
 336                 sb->s_flags |= SB_RDONLY;
 337         root_inode = sysv_iget(sb, SYSV_ROOT_INO);
 338         if (IS_ERR(root_inode)) {
 339                 printk("SysV FS: get root inode failed\n");
 340                 return 0;
 341         }
 342         sb->s_root = d_make_root(root_inode);
 343         if (!sb->s_root) {
 344                 printk("SysV FS: get root dentry failed\n");
 345                 return 0;
 346         }
 347         return 1;
 348 }
 349
 350 static int sysv_fill_super(struct super_block *sb, void *data, int silent)
 351 {
 352         struct buffer_head *bh1, *bh = NULL;
 353         struct sysv_sb_info *sbi;
 354         unsigned long blocknr;
 355         int size = 0, i;
 356
 357         BUILD_BUG_ON(1024 != sizeof (struct xenix_super_block));
 358         BUILD_BUG_ON(512 != sizeof (struct sysv4_super_block));
 359         BUILD_BUG_ON(512 != sizeof (struct sysv2_super_block));
 360         BUILD_BUG_ON(500 != sizeof (struct coh_super_block));
 361         BUILD_BUG_ON(64 != sizeof (struct sysv_inode));
 362
 363         sbi = kzalloc(sizeof(struct sysv_sb_info), GFP_KERNEL);
 364         if (!sbi)
 365                 return -ENOMEM;
 366
 367         sbi->s_sb = sb;
 368         sbi->s_block_base = 0;
 369         mutex_init(&sbi->s_lock);
 370         sb->s_fs_info = sbi;
 371         sb->s_time_min = 0;
 372         sb->s_time_max = U32_MAX;
 373         sb_set_blocksize(sb, BLOCK_SIZE);
 374
 375         for (i = 0; i < ARRAY_SIZE(flavours) && !size; i++) {
 376                 brelse(bh);
 377                 bh = sb_bread(sb, flavours[i].block);
 378                 if (!bh)
 379                         continue;
 380                 size = flavours[i].test(SYSV_SB(sb), bh);
 381         }
 382
 383         if (!size)
 384                 goto Eunknown;
 385
 386         switch (size) {
 387                 case 1:
 388                         blocknr = bh->b_blocknr << 1;
 389                         brelse(bh);
 390                         sb_set_blocksize(sb, 512);
 391                         bh1 = sb_bread(sb, blocknr);
 392                         bh = sb_bread(sb, blocknr + 1);
 393                         break;
 394                 case 2:
 395                         bh1 = bh;
 396                         break;
 397                 case 3:
 398                         blocknr = bh->b_blocknr >> 1;
 399                         brelse(bh);
 400                         sb_set_blocksize(sb, 2048);
 401                         bh1 = bh = sb_bread(sb, blocknr);
 402                         break;
 403                 default:
 404                         goto Ebadsize;
 405         }
 406
 407         if (bh && bh1) {
 408                 sbi->s_bh1 = bh1;
 409                 sbi->s_bh2 = bh;
 410                 if (complete_read_super(sb, silent, size))
 411                         return 0;
 412         }
 413
 414         brelse(bh1);
 415         brelse(bh);
 416         sb_set_blocksize(sb, BLOCK_SIZE);
 417         printk("oldfs: cannot read superblock\n");
 418 failed:
 419         kfree(sbi);
 420         return -EINVAL;
 421
 422 Eunknown:
 423         brelse(bh);
 424         if (!silent)
 425                 printk("VFS: unable to find oldfs superblock on device %s\n",
 426                         sb->s_id);
 427         goto failed;
 428 Ebadsize:
 429         brelse(bh);
 430         if (!silent)
 431                 printk("VFS: oldfs: unsupported block size (%dKb)\n",
 432                         1<<(size-2));
 433         goto failed;
 434 }
 435
 436 static int v7_sanity_check(struct super_block *sb, struct buffer_head *bh)
 437 {
 438         struct v7_super_block *v7sb;
 439         struct sysv_inode *v7i;
 440         struct buffer_head *bh2;
 441         struct sysv_sb_info *sbi;
 442
 443         sbi = sb->s_fs_info;
 444
 445         /* plausibility check on superblock */
 446         v7sb = (struct v7_super_block *) bh->b_data;
 447         if (fs16_to_cpu(sbi, v7sb->s_nfree) > V7_NICFREE ||
 448             fs16_to_cpu(sbi, v7sb->s_ninode) > V7_NICINOD ||
 449             fs32_to_cpu(sbi, v7sb->s_fsize) > V7_MAXSIZE)
 450                 return 0;
 451
 452         /* plausibility check on root inode: it is a directory,
 453            with a nonzero size that is a multiple of 16 */
 454         bh2 = sb_bread(sb, 2);
 455         if (bh2 == NULL)
 456                 return 0;
 457
 458         v7i = (struct sysv_inode *)(bh2->b_data + 64);
 459         if ((fs16_to_cpu(sbi, v7i->i_mode) & ~0777) != S_IFDIR ||
 460             (fs32_to_cpu(sbi, v7i->i_size) == 0) ||
 461             (fs32_to_cpu(sbi, v7i->i_size) & 017) ||
 462             (fs32_to_cpu(sbi, v7i->i_size) > V7_NFILES *
 463              sizeof(struct sysv_dir_entry))) {
 464                 brelse(bh2);
 465                 return 0;
 466         }
 467
 468         brelse(bh2);
 469         return 1;
 470 }
 471
 472 static int v7_fill_super(struct super_block *sb, void *data, int silent)
 473 {
 474         struct sysv_sb_info *sbi;
 475         struct buffer_head *bh;
 476
 477         if (440 != sizeof (struct v7_super_block))
 478                 panic("V7 FS: bad super-block size");
 479         if (64 != sizeof (struct sysv_inode))
 480                 panic("sysv fs: bad i-node size");
 481
 482         sbi = kzalloc(sizeof(struct sysv_sb_info), GFP_KERNEL);
 483         if (!sbi)
 484                 return -ENOMEM;
 485
 486         sbi->s_sb = sb;
 487         sbi->s_block_base = 0;
 488         sbi->s_type = FSTYPE_V7;
 489         mutex_init(&sbi->s_lock);
 490         sb->s_fs_info = sbi;
 491         sb->s_time_min = 0;
 492         sb->s_time_max = U32_MAX;
 493
 494         sb_set_blocksize(sb, 512);
 495
 496         if ((bh = sb_bread(sb, 1)) == NULL) {
 497                 if (!silent)
 498                         printk("VFS: unable to read V7 FS superblock on "
 499                                "device %s.\n", sb->s_id);
 500                 goto failed;
 501         }
 502
 503         /* Try PDP-11 UNIX */
 504         sbi->s_bytesex = BYTESEX_PDP;
 505         if (v7_sanity_check(sb, bh))
 506                 goto detected;
 507
 508         /* Try PC/IX, v7/x86 */
 509         sbi->s_bytesex = BYTESEX_LE;
 510         if (v7_sanity_check(sb, bh))
 511                 goto detected;
 512
 513         goto failed;
 514
 515 detected:
 516         sbi->s_bh1 = bh;
 517         sbi->s_bh2 = bh;
 518         if (complete_read_super(sb, silent, 1))
 519                 return 0;
 520
 521 failed:
 522         printk(KERN_ERR "VFS: could not find a valid V7 on %s.\n",
 523                 sb->s_id);
 524         brelse(bh);
 525         kfree(sbi);
 526         return -EINVAL;
 527 }
 528
 529 /* Every kernel module contains stuff like this. */
 530
 531 static struct dentry *sysv_mount(struct file_system_type *fs_type,
 532         int flags, const char *dev_name, void *data)
 533 {
 534         return mount_bdev(fs_type, flags, dev_name, data, sysv_fill_super);
 535 }
 536
 537 static struct dentry *v7_mount(struct file_system_type *fs_type,
 538         int flags, const char *dev_name, void *data)
 539 {
 540         return mount_bdev(fs_type, flags, dev_name, data, v7_fill_super);
 541 }
 542
 543 static struct file_system_type sysv_fs_type = {
 544         .owner          = THIS_MODULE,
 545         .name           = "sysv",
 546         .mount          = sysv_mount,
 547         .kill_sb        = kill_block_super,
 548         .fs_flags       = FS_REQUIRES_DEV,
 549 };
 550 MODULE_ALIAS_FS("sysv");
 551
 552 static struct file_system_type v7_fs_type = {
 553         .owner          = THIS_MODULE,
 554         .name           = "v7",
 555         .mount          = v7_mount,
 556         .kill_sb        = kill_block_super,
 557         .fs_flags       = FS_REQUIRES_DEV,
 558 };
 559 MODULE_ALIAS_FS("v7");
 560 MODULE_ALIAS("v7");
 561
 562 static int __init init_sysv_fs(void)
 563 {
 564         int error;
 565
 566         error = sysv_init_icache();
 567         if (error)
 568                 goto out;
 569         error = register_filesystem(&sysv_fs_type);
 570         if (error)
 571                 goto destroy_icache;
 572         error = register_filesystem(&v7_fs_type);
 573         if (error)
 574                 goto unregister;
 575         return 0;
 576
 577 unregister:
 578         unregister_filesystem(&sysv_fs_type);
 579 destroy_icache:
 580         sysv_destroy_icache();
 581 out:
 582         return error;
 583 }
 584
 585 static void __exit exit_sysv_fs(void)
 586 {
 587         unregister_filesystem(&sysv_fs_type);
 588         unregister_filesystem(&v7_fs_type);
 589         sysv_destroy_icache();
 590 }
 591
 592 module_init(init_sysv_fs)
 593 module_exit(exit_sysv_fs)
 594 MODULE_LICENSE("GPL");