fs/minix/inode.c

   1 /*
   2  *  linux/fs/minix/inode.c
   3  *
   4  *  Copyright (C) 1991, 1992  Linus Torvalds
   5  *
   6  *  Copyright (C) 1996  Gertjan van Wingerde    (gertjan@cs.vu.nl)
   7  *      Minix V2 fs support.
   8  *
   9  *  Modified for 680x0 by Andreas Schwab
  10  *  Updated to filesystem version 3 by Daniel Aragones
  11  */
  12
  13 #include <linux/module.h>
  14 #include "minix.h"
  15 #include <linux/buffer_head.h>
  16 #include <linux/slab.h>
  17 #include <linux/init.h>
  18 #include <linux/highuid.h>
  19 #include <linux/vfs.h>
  20
  21 static void minix_read_inode(struct inode * inode);
  22 static int minix_write_inode(struct inode * inode, int wait);
  23 static int minix_statfs(struct dentry *dentry, struct kstatfs *buf);
  24 static int minix_remount (struct super_block * sb, int * flags, char * data);
  25
  26 static void minix_delete_inode(struct inode *inode)
  27 {
  28         truncate_inode_pages(&inode->i_data, 0);
  29         inode->i_size = 0;
  30         minix_truncate(inode);
  31         minix_free_inode(inode);
  32 }
  33
  34 static void minix_put_super(struct super_block *sb)
  35 {
  36         int i;
  37         struct minix_sb_info *sbi = minix_sb(sb);
  38
  39         if (!(sb->s_flags & MS_RDONLY)) {
  40                 if (sbi->s_version != MINIX_V3)  /* s_state is now out from V3 sb */
  41                         sbi->s_ms->s_state = sbi->s_mount_state;
  42                 mark_buffer_dirty(sbi->s_sbh);
  43         }
  44         for (i = 0; i < sbi->s_imap_blocks; i++)
  45                 brelse(sbi->s_imap[i]);
  46         for (i = 0; i < sbi->s_zmap_blocks; i++)
  47                 brelse(sbi->s_zmap[i]);
  48         brelse (sbi->s_sbh);
  49         kfree(sbi->s_imap);
  50         sb->s_fs_info = NULL;
  51         kfree(sbi);
  52
  53         return;
  54 }
  55
  56 static struct kmem_cache * minix_inode_cachep;
  57
  58 static struct inode *minix_alloc_inode(struct super_block *sb)
  59 {
  60         struct minix_inode_info *ei;
  61         ei = (struct minix_inode_info *)kmem_cache_alloc(minix_inode_cachep, GFP_KERNEL);
  62         if (!ei)
  63                 return NULL;
  64         return &ei->vfs_inode;
  65 }
  66
  67 static void minix_destroy_inode(struct inode *inode)
  68 {
  69         kmem_cache_free(minix_inode_cachep, minix_i(inode));
  70 }
  71
  72 static void init_once(void * foo, struct kmem_cache * cachep, unsigned long flags)
  73 {
  74         struct minix_inode_info *ei = (struct minix_inode_info *) foo;
  75
  76         if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
  77             SLAB_CTOR_CONSTRUCTOR)
  78                 inode_init_once(&ei->vfs_inode);
  79 }
  80
  81 static int init_inodecache(void)
  82 {
  83         minix_inode_cachep = kmem_cache_create("minix_inode_cache",
  84                                              sizeof(struct minix_inode_info),
  85                                              0, (SLAB_RECLAIM_ACCOUNT|
  86                                                 SLAB_MEM_SPREAD),
  87                                              init_once, NULL);
  88         if (minix_inode_cachep == NULL)
  89                 return -ENOMEM;
  90         return 0;
  91 }
  92
  93 static void destroy_inodecache(void)
  94 {
  95         kmem_cache_destroy(minix_inode_cachep);
  96 }
  97
  98 static struct super_operations minix_sops = {
  99         .alloc_inode    = minix_alloc_inode,
 100         .destroy_inode  = minix_destroy_inode,
 101         .read_inode     = minix_read_inode,
 102         .write_inode    = minix_write_inode,
 103         .delete_inode   = minix_delete_inode,
 104         .put_super      = minix_put_super,
 105         .statfs         = minix_statfs,
 106         .remount_fs     = minix_remount,
 107 };
 108
 109 static int minix_remount (struct super_block * sb, int * flags, char * data)
 110 {
 111         struct minix_sb_info * sbi = minix_sb(sb);
 112         struct minix_super_block * ms;
 113
 114         ms = sbi->s_ms;
 115         if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
 116                 return 0;
 117         if (*flags & MS_RDONLY) {
 118                 if (ms->s_state & MINIX_VALID_FS ||
 119                     !(sbi->s_mount_state & MINIX_VALID_FS))
 120                         return 0;
 121                 /* Mounting a rw partition read-only. */
 122                 if (sbi->s_version != MINIX_V3)
 123                         ms->s_state = sbi->s_mount_state;
 124                 mark_buffer_dirty(sbi->s_sbh);
 125         } else {
 126                 /* Mount a partition which is read-only, read-write. */
 127                 if (sbi->s_version != MINIX_V3) {
 128                         sbi->s_mount_state = ms->s_state;
 129                         ms->s_state &= ~MINIX_VALID_FS;
 130                 } else {
 131                         sbi->s_mount_state = MINIX_VALID_FS;
 132                 }
 133                 mark_buffer_dirty(sbi->s_sbh);
 134
 135                 if (!(sbi->s_mount_state & MINIX_VALID_FS))
 136                         printk("MINIX-fs warning: remounting unchecked fs, "
 137                                 "running fsck is recommended\n");
 138                 else if ((sbi->s_mount_state & MINIX_ERROR_FS))
 139                         printk("MINIX-fs warning: remounting fs with errors, "
 140                                 "running fsck is recommended\n");
 141         }
 142         return 0;
 143 }
 144
 145 static int minix_fill_super(struct super_block *s, void *data, int silent)
 146 {
 147         struct buffer_head *bh;
 148         struct buffer_head **map;
 149         struct minix_super_block *ms;
 150         struct minix3_super_block *m3s = NULL;
 151         unsigned long i, block;
 152         struct inode *root_inode;
 153         struct minix_sb_info *sbi;
 154
 155         sbi = kzalloc(sizeof(struct minix_sb_info), GFP_KERNEL);
 156         if (!sbi)
 157                 return -ENOMEM;
 158         s->s_fs_info = sbi;
 159
 160         BUILD_BUG_ON(32 != sizeof (struct minix_inode));
 161         BUILD_BUG_ON(64 != sizeof(struct minix2_inode));
 162
 163         if (!sb_set_blocksize(s, BLOCK_SIZE))
 164                 goto out_bad_hblock;
 165
 166         if (!(bh = sb_bread(s, 1)))
 167                 goto out_bad_sb;
 168
 169         ms = (struct minix_super_block *) bh->b_data;
 170         sbi->s_ms = ms;
 171         sbi->s_sbh = bh;
 172         sbi->s_mount_state = ms->s_state;
 173         sbi->s_ninodes = ms->s_ninodes;
 174         sbi->s_nzones = ms->s_nzones;
 175         sbi->s_imap_blocks = ms->s_imap_blocks;
 176         sbi->s_zmap_blocks = ms->s_zmap_blocks;
 177         sbi->s_firstdatazone = ms->s_firstdatazone;
 178         sbi->s_log_zone_size = ms->s_log_zone_size;
 179         sbi->s_max_size = ms->s_max_size;
 180         s->s_magic = ms->s_magic;
 181         if (s->s_magic == MINIX_SUPER_MAGIC) {
 182                 sbi->s_version = MINIX_V1;
 183                 sbi->s_dirsize = 16;
 184                 sbi->s_namelen = 14;
 185                 sbi->s_link_max = MINIX_LINK_MAX;
 186         } else if (s->s_magic == MINIX_SUPER_MAGIC2) {
 187                 sbi->s_version = MINIX_V1;
 188                 sbi->s_dirsize = 32;
 189                 sbi->s_namelen = 30;
 190                 sbi->s_link_max = MINIX_LINK_MAX;
 191         } else if (s->s_magic == MINIX2_SUPER_MAGIC) {
 192                 sbi->s_version = MINIX_V2;
 193                 sbi->s_nzones = ms->s_zones;
 194                 sbi->s_dirsize = 16;
 195                 sbi->s_namelen = 14;
 196                 sbi->s_link_max = MINIX2_LINK_MAX;
 197         } else if (s->s_magic == MINIX2_SUPER_MAGIC2) {
 198                 sbi->s_version = MINIX_V2;
 199                 sbi->s_nzones = ms->s_zones;
 200                 sbi->s_dirsize = 32;
 201                 sbi->s_namelen = 30;
 202                 sbi->s_link_max = MINIX2_LINK_MAX;
 203         } else if ( *(__u16 *)(bh->b_data + 24) == MINIX3_SUPER_MAGIC) {
 204                 m3s = (struct minix3_super_block *) bh->b_data;
 205                 s->s_magic = m3s->s_magic;
 206                 sbi->s_imap_blocks = m3s->s_imap_blocks;
 207                 sbi->s_zmap_blocks = m3s->s_zmap_blocks;
 208                 sbi->s_firstdatazone = m3s->s_firstdatazone;
 209                 sbi->s_log_zone_size = m3s->s_log_zone_size;
 210                 sbi->s_max_size = m3s->s_max_size;
 211                 sbi->s_ninodes = m3s->s_ninodes;
 212                 sbi->s_nzones = m3s->s_zones;
 213                 sbi->s_dirsize = 64;
 214                 sbi->s_namelen = 60;
 215                 sbi->s_version = MINIX_V3;
 216                 sbi->s_link_max = MINIX2_LINK_MAX;
 217                 sbi->s_mount_state = MINIX_VALID_FS;
 218                 sb_set_blocksize(s, m3s->s_blocksize);
 219         } else
 220                 goto out_no_fs;
 221
 222         /*
 223          * Allocate the buffer map to keep the superblock small.
 224          */
 225         if (sbi->s_imap_blocks == 0 || sbi->s_zmap_blocks == 0)
 226                 goto out_illegal_sb;
 227         i = (sbi->s_imap_blocks + sbi->s_zmap_blocks) * sizeof(bh);
 228         map = kzalloc(i, GFP_KERNEL);
 229         if (!map)
 230                 goto out_no_map;
 231         sbi->s_imap = &map[0];
 232         sbi->s_zmap = &map[sbi->s_imap_blocks];
 233
 234         block=2;
 235         for (i=0 ; i < sbi->s_imap_blocks ; i++) {
 236                 if (!(sbi->s_imap[i]=sb_bread(s, block)))
 237                         goto out_no_bitmap;
 238                 block++;
 239         }
 240         for (i=0 ; i < sbi->s_zmap_blocks ; i++) {
 241                 if (!(sbi->s_zmap[i]=sb_bread(s, block)))
 242                         goto out_no_bitmap;
 243                 block++;
 244         }
 245
 246         minix_set_bit(0,sbi->s_imap[0]->b_data);
 247         minix_set_bit(0,sbi->s_zmap[0]->b_data);
 248
 249         /* set up enough so that it can read an inode */
 250         s->s_op = &minix_sops;
 251         root_inode = iget(s, MINIX_ROOT_INO);
 252         if (!root_inode || is_bad_inode(root_inode))
 253                 goto out_no_root;
 254
 255         s->s_root = d_alloc_root(root_inode);
 256         if (!s->s_root)
 257                 goto out_iput;
 258
 259         if (!NO_TRUNCATE)
 260                 s->s_root->d_op = &minix_dentry_operations;
 261
 262         if (!(s->s_flags & MS_RDONLY)) {
 263                 if (sbi->s_version != MINIX_V3) /* s_state is now out from V3 sb */
 264                         ms->s_state &= ~MINIX_VALID_FS;
 265                 mark_buffer_dirty(bh);
 266         }
 267         if (!(sbi->s_mount_state & MINIX_VALID_FS))
 268                 printk("MINIX-fs: mounting unchecked file system, "
 269                         "running fsck is recommended\n");
 270         else if (sbi->s_mount_state & MINIX_ERROR_FS)
 271                 printk("MINIX-fs: mounting file system with errors, "
 272                         "running fsck is recommended\n");
 273         return 0;
 274
 275 out_iput:
 276         iput(root_inode);
 277         goto out_freemap;
 278
 279 out_no_root:
 280         if (!silent)
 281                 printk("MINIX-fs: get root inode failed\n");
 282         goto out_freemap;
 283
 284 out_no_bitmap:
 285         printk("MINIX-fs: bad superblock or unable to read bitmaps\n");
 286 out_freemap:
 287         for (i = 0; i < sbi->s_imap_blocks; i++)
 288                 brelse(sbi->s_imap[i]);
 289         for (i = 0; i < sbi->s_zmap_blocks; i++)
 290                 brelse(sbi->s_zmap[i]);
 291         kfree(sbi->s_imap);
 292         goto out_release;
 293
 294 out_no_map:
 295         if (!silent)
 296                 printk("MINIX-fs: can't allocate map\n");
 297         goto out_release;
 298
 299 out_illegal_sb:
 300         if (!silent)
 301                 printk("MINIX-fs: bad superblock\n");
 302         goto out_release;
 303
 304 out_no_fs:
 305         if (!silent)
 306                 printk("VFS: Can't find a Minix filesystem V1 | V2 | V3 "
 307                        "on device %s.\n", s->s_id);
 308 out_release:
 309         brelse(bh);
 310         goto out;
 311
 312 out_bad_hblock:
 313         printk("MINIX-fs: blocksize too small for device\n");
 314         goto out;
 315
 316 out_bad_sb:
 317         printk("MINIX-fs: unable to read superblock\n");
 318 out:
 319         s->s_fs_info = NULL;
 320         kfree(sbi);
 321         return -EINVAL;
 322 }
 323
 324 static int minix_statfs(struct dentry *dentry, struct kstatfs *buf)
 325 {
 326         struct minix_sb_info *sbi = minix_sb(dentry->d_sb);
 327         buf->f_type = dentry->d_sb->s_magic;
 328         buf->f_bsize = dentry->d_sb->s_blocksize;
 329         buf->f_blocks = (sbi->s_nzones - sbi->s_firstdatazone) << sbi->s_log_zone_size;
 330         buf->f_bfree = minix_count_free_blocks(sbi);
 331         buf->f_bavail = buf->f_bfree;
 332         buf->f_files = sbi->s_ninodes;
 333         buf->f_ffree = minix_count_free_inodes(sbi);
 334         buf->f_namelen = sbi->s_namelen;
 335         return 0;
 336 }
 337
 338 static int minix_get_block(struct inode *inode, sector_t block,
 339                     struct buffer_head *bh_result, int create)
 340 {
 341         if (INODE_VERSION(inode) == MINIX_V1)
 342                 return V1_minix_get_block(inode, block, bh_result, create);
 343         else
 344                 return V2_minix_get_block(inode, block, bh_result, create);
 345 }
 346
 347 static int minix_writepage(struct page *page, struct writeback_control *wbc)
 348 {
 349         return block_write_full_page(page, minix_get_block, wbc);
 350 }
 351 static int minix_readpage(struct file *file, struct page *page)
 352 {
 353         return block_read_full_page(page,minix_get_block);
 354 }
 355 static int minix_prepare_write(struct file *file, struct page *page, unsigned from, unsigned to)
 356 {
 357         return block_prepare_write(page,from,to,minix_get_block);
 358 }
 359 static sector_t minix_bmap(struct address_space *mapping, sector_t block)
 360 {
 361         return generic_block_bmap(mapping,block,minix_get_block);
 362 }
 363 static const struct address_space_operations minix_aops = {
 364         .readpage = minix_readpage,
 365         .writepage = minix_writepage,
 366         .sync_page = block_sync_page,
 367         .prepare_write = minix_prepare_write,
 368         .commit_write = generic_commit_write,
 369         .bmap = minix_bmap
 370 };
 371
 372 static const struct inode_operations minix_symlink_inode_operations = {
 373         .readlink       = generic_readlink,
 374         .follow_link    = page_follow_link_light,
 375         .put_link       = page_put_link,
 376         .getattr        = minix_getattr,
 377 };
 378
 379 void minix_set_inode(struct inode *inode, dev_t rdev)
 380 {
 381         if (S_ISREG(inode->i_mode)) {
 382                 inode->i_op = &minix_file_inode_operations;
 383                 inode->i_fop = &minix_file_operations;
 384                 inode->i_mapping->a_ops = &minix_aops;
 385         } else if (S_ISDIR(inode->i_mode)) {
 386                 inode->i_op = &minix_dir_inode_operations;
 387                 inode->i_fop = &minix_dir_operations;
 388                 inode->i_mapping->a_ops = &minix_aops;
 389         } else if (S_ISLNK(inode->i_mode)) {
 390                 inode->i_op = &minix_symlink_inode_operations;
 391                 inode->i_mapping->a_ops = &minix_aops;
 392         } else
 393                 init_special_inode(inode, inode->i_mode, rdev);
 394 }
 395
 396 /*
 397  * The minix V1 function to read an inode.
 398  */
 399 static void V1_minix_read_inode(struct inode * inode)
 400 {
 401         struct buffer_head * bh;
 402         struct minix_inode * raw_inode;
 403         struct minix_inode_info *minix_inode = minix_i(inode);
 404         int i;
 405
 406         raw_inode = minix_V1_raw_inode(inode->i_sb, inode->i_ino, &bh);
 407         if (!raw_inode) {
 408                 make_bad_inode(inode);
 409                 return;
 410         }
 411         inode->i_mode = raw_inode->i_mode;
 412         inode->i_uid = (uid_t)raw_inode->i_uid;
 413         inode->i_gid = (gid_t)raw_inode->i_gid;
 414         inode->i_nlink = raw_inode->i_nlinks;
 415         inode->i_size = raw_inode->i_size;
 416         inode->i_mtime.tv_sec = inode->i_atime.tv_sec = inode->i_ctime.tv_sec = raw_inode->i_time;
 417         inode->i_mtime.tv_nsec = 0;
 418         inode->i_atime.tv_nsec = 0;
 419         inode->i_ctime.tv_nsec = 0;
 420         inode->i_blocks = 0;
 421         for (i = 0; i < 9; i++)
 422                 minix_inode->u.i1_data[i] = raw_inode->i_zone[i];
 423         minix_set_inode(inode, old_decode_dev(raw_inode->i_zone[0]));
 424         brelse(bh);
 425 }
 426
 427 /*
 428  * The minix V2 function to read an inode.
 429  */
 430 static void V2_minix_read_inode(struct inode * inode)
 431 {
 432         struct buffer_head * bh;
 433         struct minix2_inode * raw_inode;
 434         struct minix_inode_info *minix_inode = minix_i(inode);
 435         int i;
 436
 437         raw_inode = minix_V2_raw_inode(inode->i_sb, inode->i_ino, &bh);
 438         if (!raw_inode) {
 439                 make_bad_inode(inode);
 440                 return;
 441         }
 442         inode->i_mode = raw_inode->i_mode;
 443         inode->i_uid = (uid_t)raw_inode->i_uid;
 444         inode->i_gid = (gid_t)raw_inode->i_gid;
 445         inode->i_nlink = raw_inode->i_nlinks;
 446         inode->i_size = raw_inode->i_size;
 447         inode->i_mtime.tv_sec = raw_inode->i_mtime;
 448         inode->i_atime.tv_sec = raw_inode->i_atime;
 449         inode->i_ctime.tv_sec = raw_inode->i_ctime;
 450         inode->i_mtime.tv_nsec = 0;
 451         inode->i_atime.tv_nsec = 0;
 452         inode->i_ctime.tv_nsec = 0;
 453         inode->i_blocks = 0;
 454         for (i = 0; i < 10; i++)
 455                 minix_inode->u.i2_data[i] = raw_inode->i_zone[i];
 456         minix_set_inode(inode, old_decode_dev(raw_inode->i_zone[0]));
 457         brelse(bh);
 458 }
 459
 460 /*
 461  * The global function to read an inode.
 462  */
 463 static void minix_read_inode(struct inode * inode)
 464 {
 465         if (INODE_VERSION(inode) == MINIX_V1)
 466                 V1_minix_read_inode(inode);
 467         else
 468                 V2_minix_read_inode(inode);
 469 }
 470
 471 /*
 472  * The minix V1 function to synchronize an inode.
 473  */
 474 static struct buffer_head * V1_minix_update_inode(struct inode * inode)
 475 {
 476         struct buffer_head * bh;
 477         struct minix_inode * raw_inode;
 478         struct minix_inode_info *minix_inode = minix_i(inode);
 479         int i;
 480
 481         raw_inode = minix_V1_raw_inode(inode->i_sb, inode->i_ino, &bh);
 482         if (!raw_inode)
 483                 return NULL;
 484         raw_inode->i_mode = inode->i_mode;
 485         raw_inode->i_uid = fs_high2lowuid(inode->i_uid);
 486         raw_inode->i_gid = fs_high2lowgid(inode->i_gid);
 487         raw_inode->i_nlinks = inode->i_nlink;
 488         raw_inode->i_size = inode->i_size;
 489         raw_inode->i_time = inode->i_mtime.tv_sec;
 490         if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
 491                 raw_inode->i_zone[0] = old_encode_dev(inode->i_rdev);
 492         else for (i = 0; i < 9; i++)
 493                 raw_inode->i_zone[i] = minix_inode->u.i1_data[i];
 494         mark_buffer_dirty(bh);
 495         return bh;
 496 }
 497
 498 /*
 499  * The minix V2 function to synchronize an inode.
 500  */
 501 static struct buffer_head * V2_minix_update_inode(struct inode * inode)
 502 {
 503         struct buffer_head * bh;
 504         struct minix2_inode * raw_inode;
 505         struct minix_inode_info *minix_inode = minix_i(inode);
 506         int i;
 507
 508         raw_inode = minix_V2_raw_inode(inode->i_sb, inode->i_ino, &bh);
 509         if (!raw_inode)
 510                 return NULL;
 511         raw_inode->i_mode = inode->i_mode;
 512         raw_inode->i_uid = fs_high2lowuid(inode->i_uid);
 513         raw_inode->i_gid = fs_high2lowgid(inode->i_gid);
 514         raw_inode->i_nlinks = inode->i_nlink;
 515         raw_inode->i_size = inode->i_size;
 516         raw_inode->i_mtime = inode->i_mtime.tv_sec;
 517         raw_inode->i_atime = inode->i_atime.tv_sec;
 518         raw_inode->i_ctime = inode->i_ctime.tv_sec;
 519         if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
 520                 raw_inode->i_zone[0] = old_encode_dev(inode->i_rdev);
 521         else for (i = 0; i < 10; i++)
 522                 raw_inode->i_zone[i] = minix_inode->u.i2_data[i];
 523         mark_buffer_dirty(bh);
 524         return bh;
 525 }
 526
 527 static struct buffer_head *minix_update_inode(struct inode *inode)
 528 {
 529         if (INODE_VERSION(inode) == MINIX_V1)
 530                 return V1_minix_update_inode(inode);
 531         else
 532                 return V2_minix_update_inode(inode);
 533 }
 534
 535 static int minix_write_inode(struct inode * inode, int wait)
 536 {
 537         brelse(minix_update_inode(inode));
 538         return 0;
 539 }
 540
 541 int minix_sync_inode(struct inode * inode)
 542 {
 543         int err = 0;
 544         struct buffer_head *bh;
 545
 546         bh = minix_update_inode(inode);
 547         if (bh && buffer_dirty(bh))
 548         {
 549                 sync_dirty_buffer(bh);
 550                 if (buffer_req(bh) && !buffer_uptodate(bh))
 551                 {
 552                         printk("IO error syncing minix inode [%s:%08lx]\n",
 553                                 inode->i_sb->s_id, inode->i_ino);
 554                         err = -1;
 555                 }
 556         }
 557         else if (!bh)
 558                 err = -1;
 559         brelse (bh);
 560         return err;
 561 }
 562
 563 int minix_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
 564 {
 565         struct inode *dir = dentry->d_parent->d_inode;
 566         struct super_block *sb = dir->i_sb;
 567         generic_fillattr(dentry->d_inode, stat);
 568         if (INODE_VERSION(dentry->d_inode) == MINIX_V1)
 569                 stat->blocks = (BLOCK_SIZE / 512) * V1_minix_blocks(stat->size, sb);
 570         else
 571                 stat->blocks = (sb->s_blocksize / 512) * V2_minix_blocks(stat->size, sb);
 572         stat->blksize = sb->s_blocksize;
 573         return 0;
 574 }
 575
 576 /*
 577  * The function that is called for file truncation.
 578  */
 579 void minix_truncate(struct inode * inode)
 580 {
 581         if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)))
 582                 return;
 583         if (INODE_VERSION(inode) == MINIX_V1)
 584                 V1_minix_truncate(inode);
 585         else
 586                 V2_minix_truncate(inode);
 587 }
 588
 589 static int minix_get_sb(struct file_system_type *fs_type,
 590         int flags, const char *dev_name, void *data, struct vfsmount *mnt)
 591 {
 592         return get_sb_bdev(fs_type, flags, dev_name, data, minix_fill_super,
 593                            mnt);
 594 }
 595
 596 static struct file_system_type minix_fs_type = {
 597         .owner          = THIS_MODULE,
 598         .name           = "minix",
 599         .get_sb         = minix_get_sb,
 600         .kill_sb        = kill_block_super,
 601         .fs_flags       = FS_REQUIRES_DEV,
 602 };
 603
 604 static int __init init_minix_fs(void)
 605 {
 606         int err = init_inodecache();
 607         if (err)
 608                 goto out1;
 609         err = register_filesystem(&minix_fs_type);
 610         if (err)
 611                 goto out;
 612         return 0;
 613 out:
 614         destroy_inodecache();
 615 out1:
 616         return err;
 617 }
 618
 619 static void __exit exit_minix_fs(void)
 620 {
 621         unregister_filesystem(&minix_fs_type);
 622         destroy_inodecache();
 623 }
 624
 625 module_init(init_minix_fs)
 626 module_exit(exit_minix_fs)
 627 MODULE_LICENSE("GPL");
 628