fs/bfs/inode.c

   1 /*
   2  *      fs/bfs/inode.c
   3  *      BFS superblock and inode operations.
   4  *      Copyright (C) 1999-2006 Tigran Aivazian <tigran@aivazian.fsnet.co.uk>
   5  *      From fs/minix, Copyright (C) 1991, 1992 Linus Torvalds.
   6  *
   7  *      Made endianness-clean by Andrew Stribblehill <ads@wompom.org>, 2005.
   8  */
   9
  10 #include <linux/module.h>
  11 #include <linux/mm.h>
  12 #include <linux/slab.h>
  13 #include <linux/init.h>
  14 #include <linux/fs.h>
  15 #include <linux/smp_lock.h>
  16 #include <linux/buffer_head.h>
  17 #include <linux/vfs.h>
  18 #include <asm/uaccess.h>
  19 #include "bfs.h"
  20
  21 MODULE_AUTHOR("Tigran Aivazian <tigran@aivazian.fsnet.co.uk>");
  22 MODULE_DESCRIPTION("SCO UnixWare BFS filesystem for Linux");
  23 MODULE_LICENSE("GPL");
  24
  25 #undef DEBUG
  26
  27 #ifdef DEBUG
  28 #define dprintf(x...)   printf(x)
  29 #else
  30 #define dprintf(x...)
  31 #endif
  32
  33 static void bfs_write_super(struct super_block *s);
  34 void dump_imap(const char *prefix, struct super_block *s);
  35
  36 struct inode *bfs_iget(struct super_block *sb, unsigned long ino)
  37 {
  38         struct bfs_inode *di;
  39         struct inode *inode;
  40         struct buffer_head *bh;
  41         int block, off;
  42
  43         inode = iget_locked(sb, ino);
  44         if (IS_ERR(inode))
  45                 return ERR_PTR(-ENOMEM);
  46         if (!(inode->i_state & I_NEW))
  47                 return inode;
  48
  49         if ((ino < BFS_ROOT_INO) || (ino > BFS_SB(inode->i_sb)->si_lasti)) {
  50                 printf("Bad inode number %s:%08lx\n", inode->i_sb->s_id, ino);
  51                 goto error;
  52         }
  53
  54         block = (ino - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1;
  55         bh = sb_bread(inode->i_sb, block);
  56         if (!bh) {
  57                 printf("Unable to read inode %s:%08lx\n", inode->i_sb->s_id,
  58                                                                         ino);
  59                 goto error;
  60         }
  61
  62         off = (ino - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;
  63         di = (struct bfs_inode *)bh->b_data + off;
  64
  65         inode->i_mode = 0x0000FFFF & le32_to_cpu(di->i_mode);
  66         if (le32_to_cpu(di->i_vtype) == BFS_VDIR) {
  67                 inode->i_mode |= S_IFDIR;
  68                 inode->i_op = &bfs_dir_inops;
  69                 inode->i_fop = &bfs_dir_operations;
  70         } else if (le32_to_cpu(di->i_vtype) == BFS_VREG) {
  71                 inode->i_mode |= S_IFREG;
  72                 inode->i_op = &bfs_file_inops;
  73                 inode->i_fop = &bfs_file_operations;
  74                 inode->i_mapping->a_ops = &bfs_aops;
  75         }
  76
  77         BFS_I(inode)->i_sblock =  le32_to_cpu(di->i_sblock);
  78         BFS_I(inode)->i_eblock =  le32_to_cpu(di->i_eblock);
  79         BFS_I(inode)->i_dsk_ino = le16_to_cpu(di->i_ino);
  80         inode->i_uid =  le32_to_cpu(di->i_uid);
  81         inode->i_gid =  le32_to_cpu(di->i_gid);
  82         inode->i_nlink =  le32_to_cpu(di->i_nlink);
  83         inode->i_size = BFS_FILESIZE(di);
  84         inode->i_blocks = BFS_FILEBLOCKS(di);
  85         inode->i_atime.tv_sec =  le32_to_cpu(di->i_atime);
  86         inode->i_mtime.tv_sec =  le32_to_cpu(di->i_mtime);
  87         inode->i_ctime.tv_sec =  le32_to_cpu(di->i_ctime);
  88         inode->i_atime.tv_nsec = 0;
  89         inode->i_mtime.tv_nsec = 0;
  90         inode->i_ctime.tv_nsec = 0;
  91
  92         brelse(bh);
  93         unlock_new_inode(inode);
  94         return inode;
  95
  96 error:
  97         iget_failed(inode);
  98         return ERR_PTR(-EIO);
  99 }
 100
 101 static int bfs_write_inode(struct inode *inode, int unused)
 102 {
 103         unsigned int ino = (u16)inode->i_ino;
 104         unsigned long i_sblock;
 105         struct bfs_inode *di;
 106         struct buffer_head *bh;
 107         int block, off;
 108         struct bfs_sb_info *info = BFS_SB(inode->i_sb);
 109
 110         dprintf("ino=%08x\n", ino);
 111
 112         if ((ino < BFS_ROOT_INO) || (ino > BFS_SB(inode->i_sb)->si_lasti)) {
 113                 printf("Bad inode number %s:%08x\n", inode->i_sb->s_id, ino);
 114                 return -EIO;
 115         }
 116
 117         mutex_lock(&info->bfs_lock);
 118         block = (ino - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1;
 119         bh = sb_bread(inode->i_sb, block);
 120         if (!bh) {
 121                 printf("Unable to read inode %s:%08x\n",
 122                                 inode->i_sb->s_id, ino);
 123                 mutex_unlock(&info->bfs_lock);
 124                 return -EIO;
 125         }
 126
 127         off = (ino - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;
 128         di = (struct bfs_inode *)bh->b_data + off;
 129
 130         if (ino == BFS_ROOT_INO)
 131                 di->i_vtype = cpu_to_le32(BFS_VDIR);
 132         else
 133                 di->i_vtype = cpu_to_le32(BFS_VREG);
 134
 135         di->i_ino = cpu_to_le16(ino);
 136         di->i_mode = cpu_to_le32(inode->i_mode);
 137         di->i_uid = cpu_to_le32(inode->i_uid);
 138         di->i_gid = cpu_to_le32(inode->i_gid);
 139         di->i_nlink = cpu_to_le32(inode->i_nlink);
 140         di->i_atime = cpu_to_le32(inode->i_atime.tv_sec);
 141         di->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec);
 142         di->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec);
 143         i_sblock = BFS_I(inode)->i_sblock;
 144         di->i_sblock = cpu_to_le32(i_sblock);
 145         di->i_eblock = cpu_to_le32(BFS_I(inode)->i_eblock);
 146         di->i_eoffset = cpu_to_le32(i_sblock * BFS_BSIZE + inode->i_size - 1);
 147
 148         mark_buffer_dirty(bh);
 149         brelse(bh);
 150         mutex_unlock(&info->bfs_lock);
 151         return 0;
 152 }
 153
 154 static void bfs_delete_inode(struct inode *inode)
 155 {
 156         unsigned long ino = inode->i_ino;
 157         struct bfs_inode *di;
 158         struct buffer_head *bh;
 159         int block, off;
 160         struct super_block *s = inode->i_sb;
 161         struct bfs_sb_info *info = BFS_SB(s);
 162         struct bfs_inode_info *bi = BFS_I(inode);
 163
 164         dprintf("ino=%08lx\n", ino);
 165
 166         truncate_inode_pages(&inode->i_data, 0);
 167
 168         if ((ino < BFS_ROOT_INO) || (ino > info->si_lasti)) {
 169                 printf("invalid ino=%08lx\n", ino);
 170                 return;
 171         }
 172
 173         inode->i_size = 0;
 174         inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC;
 175         mutex_lock(&info->bfs_lock);
 176         mark_inode_dirty(inode);
 177
 178         block = (ino - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1;
 179         bh = sb_bread(s, block);
 180         if (!bh) {
 181                 printf("Unable to read inode %s:%08lx\n",
 182                                         inode->i_sb->s_id, ino);
 183                 mutex_unlock(&info->bfs_lock);
 184                 return;
 185         }
 186         off = (ino - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;
 187         di = (struct bfs_inode *)bh->b_data + off;
 188         memset((void *)di, 0, sizeof(struct bfs_inode));
 189         mark_buffer_dirty(bh);
 190         brelse(bh);
 191
 192         if (bi->i_dsk_ino) {
 193                 if (bi->i_sblock)
 194                         info->si_freeb += bi->i_eblock + 1 - bi->i_sblock;
 195                 info->si_freei++;
 196                 clear_bit(ino, info->si_imap);
 197                 dump_imap("delete_inode", s);
 198         }
 199
 200         /*
 201          * If this was the last file, make the previous block
 202          * "last block of the last file" even if there is no
 203          * real file there, saves us 1 gap.
 204          */
 205         if (info->si_lf_eblk == bi->i_eblock) {
 206                 info->si_lf_eblk = bi->i_sblock - 1;
 207                 mark_buffer_dirty(info->si_sbh);
 208         }
 209         mutex_unlock(&info->bfs_lock);
 210         clear_inode(inode);
 211 }
 212
 213 static void bfs_put_super(struct super_block *s)
 214 {
 215         struct bfs_sb_info *info = BFS_SB(s);
 216
 217         if (!info)
 218                 return;
 219
 220         lock_kernel();
 221
 222         if (s->s_dirt)
 223                 bfs_write_super(s);
 224
 225         brelse(info->si_sbh);
 226         mutex_destroy(&info->bfs_lock);
 227         kfree(info->si_imap);
 228         kfree(info);
 229         s->s_fs_info = NULL;
 230
 231         unlock_kernel();
 232 }
 233
 234 static int bfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 235 {
 236         struct super_block *s = dentry->d_sb;
 237         struct bfs_sb_info *info = BFS_SB(s);
 238         u64 id = huge_encode_dev(s->s_bdev->bd_dev);
 239         buf->f_type = BFS_MAGIC;
 240         buf->f_bsize = s->s_blocksize;
 241         buf->f_blocks = info->si_blocks;
 242         buf->f_bfree = buf->f_bavail = info->si_freeb;
 243         buf->f_files = info->si_lasti + 1 - BFS_ROOT_INO;
 244         buf->f_ffree = info->si_freei;
 245         buf->f_fsid.val[0] = (u32)id;
 246         buf->f_fsid.val[1] = (u32)(id >> 32);
 247         buf->f_namelen = BFS_NAMELEN;
 248         return 0;
 249 }
 250
 251 static void bfs_write_super(struct super_block *s)
 252 {
 253         struct bfs_sb_info *info = BFS_SB(s);
 254
 255         mutex_lock(&info->bfs_lock);
 256         if (!(s->s_flags & MS_RDONLY))
 257                 mark_buffer_dirty(info->si_sbh);
 258         s->s_dirt = 0;
 259         mutex_unlock(&info->bfs_lock);
 260 }
 261
 262 static struct kmem_cache *bfs_inode_cachep;
 263
 264 static struct inode *bfs_alloc_inode(struct super_block *sb)
 265 {
 266         struct bfs_inode_info *bi;
 267         bi = kmem_cache_alloc(bfs_inode_cachep, GFP_KERNEL);
 268         if (!bi)
 269                 return NULL;
 270         return &bi->vfs_inode;
 271 }
 272
 273 static void bfs_destroy_inode(struct inode *inode)
 274 {
 275         kmem_cache_free(bfs_inode_cachep, BFS_I(inode));
 276 }
 277
 278 static void init_once(void *foo)
 279 {
 280         struct bfs_inode_info *bi = foo;
 281
 282         inode_init_once(&bi->vfs_inode);
 283 }
 284
 285 static int init_inodecache(void)
 286 {
 287         bfs_inode_cachep = kmem_cache_create("bfs_inode_cache",
 288                                              sizeof(struct bfs_inode_info),
 289                                              0, (SLAB_RECLAIM_ACCOUNT|
 290                                                 SLAB_MEM_SPREAD),
 291                                              init_once);
 292         if (bfs_inode_cachep == NULL)
 293                 return -ENOMEM;
 294         return 0;
 295 }
 296
 297 static void destroy_inodecache(void)
 298 {
 299         kmem_cache_destroy(bfs_inode_cachep);
 300 }
 301
 302 static const struct super_operations bfs_sops = {
 303         .alloc_inode    = bfs_alloc_inode,
 304         .destroy_inode  = bfs_destroy_inode,
 305         .write_inode    = bfs_write_inode,
 306         .delete_inode   = bfs_delete_inode,
 307         .put_super      = bfs_put_super,
 308         .write_super    = bfs_write_super,
 309         .statfs         = bfs_statfs,
 310 };
 311
 312 void dump_imap(const char *prefix, struct super_block *s)
 313 {
 314 #ifdef DEBUG
 315         int i;
 316         char *tmpbuf = (char *)get_zeroed_page(GFP_KERNEL);
 317
 318         if (!tmpbuf)
 319                 return;
 320         for (i = BFS_SB(s)->si_lasti; i >= 0; i--) {
 321                 if (i > PAGE_SIZE - 100) break;
 322                 if (test_bit(i, BFS_SB(s)->si_imap))
 323                         strcat(tmpbuf, "1");
 324                 else
 325                         strcat(tmpbuf, "0");
 326         }
 327         printf("BFS-fs: %s: lasti=%08lx <%s>\n",
 328                                 prefix, BFS_SB(s)->si_lasti, tmpbuf);
 329         free_page((unsigned long)tmpbuf);
 330 #endif
 331 }
 332
 333 static int bfs_fill_super(struct super_block *s, void *data, int silent)
 334 {
 335         struct buffer_head *bh;
 336         struct bfs_super_block *bfs_sb;
 337         struct inode *inode;
 338         unsigned i, imap_len;
 339         struct bfs_sb_info *info;
 340         long ret = -EINVAL;
 341         unsigned long i_sblock, i_eblock, i_eoff, s_size;
 342
 343         info = kzalloc(sizeof(*info), GFP_KERNEL);
 344         if (!info)
 345                 return -ENOMEM;
 346         s->s_fs_info = info;
 347
 348         sb_set_blocksize(s, BFS_BSIZE);
 349
 350         bh = sb_bread(s, 0);
 351         if(!bh)
 352                 goto out;
 353         bfs_sb = (struct bfs_super_block *)bh->b_data;
 354         if (le32_to_cpu(bfs_sb->s_magic) != BFS_MAGIC) {
 355                 if (!silent)
 356                         printf("No BFS filesystem on %s (magic=%08x)\n",
 357                                 s->s_id,  le32_to_cpu(bfs_sb->s_magic));
 358                 goto out;
 359         }
 360         if (BFS_UNCLEAN(bfs_sb, s) && !silent)
 361                 printf("%s is unclean, continuing\n", s->s_id);
 362
 363         s->s_magic = BFS_MAGIC;
 364         info->si_sbh = bh;
 365
 366         if (le32_to_cpu(bfs_sb->s_start) > le32_to_cpu(bfs_sb->s_end)) {
 367                 printf("Superblock is corrupted\n");
 368                 goto out;
 369         }
 370
 371         info->si_lasti = (le32_to_cpu(bfs_sb->s_start) - BFS_BSIZE) /
 372                                         sizeof(struct bfs_inode)
 373                                         + BFS_ROOT_INO - 1;
 374         imap_len = (info->si_lasti / 8) + 1;
 375         info->si_imap = kzalloc(imap_len, GFP_KERNEL);
 376         if (!info->si_imap)
 377                 goto out;
 378         for (i = 0; i < BFS_ROOT_INO; i++)
 379                 set_bit(i, info->si_imap);
 380
 381         s->s_op = &bfs_sops;
 382         inode = bfs_iget(s, BFS_ROOT_INO);
 383         if (IS_ERR(inode)) {
 384                 ret = PTR_ERR(inode);
 385                 kfree(info->si_imap);
 386                 goto out;
 387         }
 388         s->s_root = d_alloc_root(inode);
 389         if (!s->s_root) {
 390                 iput(inode);
 391                 ret = -ENOMEM;
 392                 kfree(info->si_imap);
 393                 goto out;
 394         }
 395
 396         info->si_blocks = (le32_to_cpu(bfs_sb->s_end) + 1) >> BFS_BSIZE_BITS;
 397         info->si_freeb = (le32_to_cpu(bfs_sb->s_end) + 1
 398                         - le32_to_cpu(bfs_sb->s_start)) >> BFS_BSIZE_BITS;
 399         info->si_freei = 0;
 400         info->si_lf_eblk = 0;
 401
 402         /* can we read the last block? */
 403         bh = sb_bread(s, info->si_blocks - 1);
 404         if (!bh) {
 405                 printf("Last block not available: %lu\n", info->si_blocks - 1);
 406                 iput(inode);
 407                 ret = -EIO;
 408                 kfree(info->si_imap);
 409                 goto out;
 410         }
 411         brelse(bh);
 412
 413         bh = NULL;
 414         for (i = BFS_ROOT_INO; i <= info->si_lasti; i++) {
 415                 struct bfs_inode *di;
 416                 int block = (i - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1;
 417                 int off = (i - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;
 418                 unsigned long eblock;
 419
 420                 if (!off) {
 421                         brelse(bh);
 422                         bh = sb_bread(s, block);
 423                 }
 424
 425                 if (!bh)
 426                         continue;
 427
 428                 di = (struct bfs_inode *)bh->b_data + off;
 429
 430                 /* test if filesystem is not corrupted */
 431
 432                 i_eoff = le32_to_cpu(di->i_eoffset);
 433                 i_sblock = le32_to_cpu(di->i_sblock);
 434                 i_eblock = le32_to_cpu(di->i_eblock);
 435                 s_size = le32_to_cpu(bfs_sb->s_end);
 436
 437                 if (i_sblock > info->si_blocks ||
 438                         i_eblock > info->si_blocks ||
 439                         i_sblock > i_eblock ||
 440                         i_eoff > s_size ||
 441                         i_sblock * BFS_BSIZE > i_eoff) {
 442
 443                         printf("Inode 0x%08x corrupted\n", i);
 444
 445                         brelse(bh);
 446                         s->s_root = NULL;
 447                         kfree(info->si_imap);
 448                         kfree(info);
 449                         s->s_fs_info = NULL;
 450                         return -EIO;
 451                 }
 452
 453                 if (!di->i_ino) {
 454                         info->si_freei++;
 455                         continue;
 456                 }
 457                 set_bit(i, info->si_imap);
 458                 info->si_freeb -= BFS_FILEBLOCKS(di);
 459
 460                 eblock =  le32_to_cpu(di->i_eblock);
 461                 if (eblock > info->si_lf_eblk)
 462                         info->si_lf_eblk = eblock;
 463         }
 464         brelse(bh);
 465         if (!(s->s_flags & MS_RDONLY)) {
 466                 mark_buffer_dirty(info->si_sbh);
 467                 s->s_dirt = 1;
 468         }
 469         dump_imap("read_super", s);
 470         mutex_init(&info->bfs_lock);
 471         return 0;
 472
 473 out:
 474         brelse(bh);
 475         kfree(info);
 476         s->s_fs_info = NULL;
 477         return ret;
 478 }
 479
 480 static int bfs_get_sb(struct file_system_type *fs_type,
 481         int flags, const char *dev_name, void *data, struct vfsmount *mnt)
 482 {
 483         return get_sb_bdev(fs_type, flags, dev_name, data, bfs_fill_super, mnt);
 484 }
 485
 486 static struct file_system_type bfs_fs_type = {
 487         .owner          = THIS_MODULE,
 488         .name           = "bfs",
 489         .get_sb         = bfs_get_sb,
 490         .kill_sb        = kill_block_super,
 491         .fs_flags       = FS_REQUIRES_DEV,
 492 };
 493
 494 static int __init init_bfs_fs(void)
 495 {
 496         int err = init_inodecache();
 497         if (err)
 498                 goto out1;
 499         err = register_filesystem(&bfs_fs_type);
 500         if (err)
 501                 goto out;
 502         return 0;
 503 out:
 504         destroy_inodecache();
 505 out1:
 506         return err;
 507 }
 508
 509 static void __exit exit_bfs_fs(void)
 510 {
 511         unregister_filesystem(&bfs_fs_type);
 512         destroy_inodecache();
 513 }
 514
 515 module_init(init_bfs_fs)
 516 module_exit(exit_bfs_fs)