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