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   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 wait)
 102 {
 103         struct bfs_sb_info *info = BFS_SB(inode->i_sb);
 104         unsigned int ino = (u16)inode->i_ino;
 105         unsigned long i_sblock;
 106         struct bfs_inode *di;
 107         struct buffer_head *bh;
 108         int block, off;
 109         int err = 0;
 110
 111         dprintf("ino=%08x\n", ino);
 112
 113         if ((ino < BFS_ROOT_INO) || (ino > BFS_SB(inode->i_sb)->si_lasti)) {
 114                 printf("Bad inode number %s:%08x\n", inode->i_sb->s_id, ino);
 115                 return -EIO;
 116         }
 117
 118         mutex_lock(&info->bfs_lock);
 119         block = (ino - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1;
 120         bh = sb_bread(inode->i_sb, block);
 121         if (!bh) {
 122                 printf("Unable to read inode %s:%08x\n",
 123                                 inode->i_sb->s_id, ino);
 124                 mutex_unlock(&info->bfs_lock);
 125                 return -EIO;
 126         }
 127
 128         off = (ino - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;
 129         di = (struct bfs_inode *)bh->b_data + off;
 130
 131         if (ino == BFS_ROOT_INO)
 132                 di->i_vtype = cpu_to_le32(BFS_VDIR);
 133         else
 134                 di->i_vtype = cpu_to_le32(BFS_VREG);
 135
 136         di->i_ino = cpu_to_le16(ino);
 137         di->i_mode = cpu_to_le32(inode->i_mode);
 138         di->i_uid = cpu_to_le32(inode->i_uid);
 139         di->i_gid = cpu_to_le32(inode->i_gid);
 140         di->i_nlink = cpu_to_le32(inode->i_nlink);
 141         di->i_atime = cpu_to_le32(inode->i_atime.tv_sec);
 142         di->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec);
 143         di->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec);
 144         i_sblock = BFS_I(inode)->i_sblock;
 145         di->i_sblock = cpu_to_le32(i_sblock);
 146         di->i_eblock = cpu_to_le32(BFS_I(inode)->i_eblock);
 147         di->i_eoffset = cpu_to_le32(i_sblock * BFS_BSIZE + inode->i_size - 1);
 148
 149         mark_buffer_dirty(bh);
 150         if (wait) {
 151                 sync_dirty_buffer(bh);
 152                 if (buffer_req(bh) && !buffer_uptodate(bh))
 153                         err = -EIO;
 154         }
 155         brelse(bh);
 156         mutex_unlock(&info->bfs_lock);
 157         return err;
 158 }
 159
 160 static void bfs_delete_inode(struct inode *inode)
 161 {
 162         unsigned long ino = inode->i_ino;
 163         struct bfs_inode *di;
 164         struct buffer_head *bh;
 165         int block, off;
 166         struct super_block *s = inode->i_sb;
 167         struct bfs_sb_info *info = BFS_SB(s);
 168         struct bfs_inode_info *bi = BFS_I(inode);
 169
 170         dprintf("ino=%08lx\n", ino);
 171
 172         truncate_inode_pages(&inode->i_data, 0);
 173
 174         if ((ino < BFS_ROOT_INO) || (ino > info->si_lasti)) {
 175                 printf("invalid ino=%08lx\n", ino);
 176                 return;
 177         }
 178
 179         inode->i_size = 0;
 180         inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC;
 181         mutex_lock(&info->bfs_lock);
 182         mark_inode_dirty(inode);
 183
 184         block = (ino - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1;
 185         bh = sb_bread(s, block);
 186         if (!bh) {
 187                 printf("Unable to read inode %s:%08lx\n",
 188                                         inode->i_sb->s_id, ino);
 189                 mutex_unlock(&info->bfs_lock);
 190                 return;
 191         }
 192         off = (ino - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;
 193         di = (struct bfs_inode *)bh->b_data + off;
 194         memset((void *)di, 0, sizeof(struct bfs_inode));
 195         mark_buffer_dirty(bh);
 196         brelse(bh);
 197
 198         if (bi->i_dsk_ino) {
 199                 if (bi->i_sblock)
 200                         info->si_freeb += bi->i_eblock + 1 - bi->i_sblock;
 201                 info->si_freei++;
 202                 clear_bit(ino, info->si_imap);
 203                 dump_imap("delete_inode", s);
 204         }
 205
 206         /*
 207          * If this was the last file, make the previous block
 208          * "last block of the last file" even if there is no
 209          * real file there, saves us 1 gap.
 210          */
 211         if (info->si_lf_eblk == bi->i_eblock) {
 212                 info->si_lf_eblk = bi->i_sblock - 1;
 213                 mark_buffer_dirty(info->si_sbh);
 214         }
 215         mutex_unlock(&info->bfs_lock);
 216         clear_inode(inode);
 217 }
 218
 219 static void bfs_put_super(struct super_block *s)
 220 {
 221         struct bfs_sb_info *info = BFS_SB(s);
 222
 223         if (!info)
 224                 return;
 225
 226         lock_kernel();
 227
 228         if (s->s_dirt)
 229                 bfs_write_super(s);
 230
 231         brelse(info->si_sbh);
 232         mutex_destroy(&info->bfs_lock);
 233         kfree(info->si_imap);
 234         kfree(info);
 235         s->s_fs_info = NULL;
 236
 237         unlock_kernel();
 238 }
 239
 240 static int bfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 241 {
 242         struct super_block *s = dentry->d_sb;
 243         struct bfs_sb_info *info = BFS_SB(s);
 244         u64 id = huge_encode_dev(s->s_bdev->bd_dev);
 245         buf->f_type = BFS_MAGIC;
 246         buf->f_bsize = s->s_blocksize;
 247         buf->f_blocks = info->si_blocks;
 248         buf->f_bfree = buf->f_bavail = info->si_freeb;
 249         buf->f_files = info->si_lasti + 1 - BFS_ROOT_INO;
 250         buf->f_ffree = info->si_freei;
 251         buf->f_fsid.val[0] = (u32)id;
 252         buf->f_fsid.val[1] = (u32)(id >> 32);
 253         buf->f_namelen = BFS_NAMELEN;
 254         return 0;
 255 }
 256
 257 static void bfs_write_super(struct super_block *s)
 258 {
 259         struct bfs_sb_info *info = BFS_SB(s);
 260
 261         mutex_lock(&info->bfs_lock);
 262         if (!(s->s_flags & MS_RDONLY))
 263                 mark_buffer_dirty(info->si_sbh);
 264         s->s_dirt = 0;
 265         mutex_unlock(&info->bfs_lock);
 266 }
 267
 268 static struct kmem_cache *bfs_inode_cachep;
 269
 270 static struct inode *bfs_alloc_inode(struct super_block *sb)
 271 {
 272         struct bfs_inode_info *bi;
 273         bi = kmem_cache_alloc(bfs_inode_cachep, GFP_KERNEL);
 274         if (!bi)
 275                 return NULL;
 276         return &bi->vfs_inode;
 277 }
 278
 279 static void bfs_destroy_inode(struct inode *inode)
 280 {
 281         kmem_cache_free(bfs_inode_cachep, BFS_I(inode));
 282 }
 283
 284 static void init_once(void *foo)
 285 {
 286         struct bfs_inode_info *bi = foo;
 287
 288         inode_init_once(&bi->vfs_inode);
 289 }
 290
 291 static int init_inodecache(void)
 292 {
 293         bfs_inode_cachep = kmem_cache_create("bfs_inode_cache",
 294                                              sizeof(struct bfs_inode_info),
 295                                              0, (SLAB_RECLAIM_ACCOUNT|
 296                                                 SLAB_MEM_SPREAD),
 297                                              init_once);
 298         if (bfs_inode_cachep == NULL)
 299                 return -ENOMEM;
 300         return 0;
 301 }
 302
 303 static void destroy_inodecache(void)
 304 {
 305         kmem_cache_destroy(bfs_inode_cachep);
 306 }
 307
 308 static const struct super_operations bfs_sops = {
 309         .alloc_inode    = bfs_alloc_inode,
 310         .destroy_inode  = bfs_destroy_inode,
 311         .write_inode    = bfs_write_inode,
 312         .delete_inode   = bfs_delete_inode,
 313         .put_super      = bfs_put_super,
 314         .write_super    = bfs_write_super,
 315         .statfs         = bfs_statfs,
 316 };
 317
 318 void dump_imap(const char *prefix, struct super_block *s)
 319 {
 320 #ifdef DEBUG
 321         int i;
 322         char *tmpbuf = (char *)get_zeroed_page(GFP_KERNEL);
 323
 324         if (!tmpbuf)
 325                 return;
 326         for (i = BFS_SB(s)->si_lasti; i >= 0; i--) {
 327                 if (i > PAGE_SIZE - 100) break;
 328                 if (test_bit(i, BFS_SB(s)->si_imap))
 329                         strcat(tmpbuf, "1");
 330                 else
 331                         strcat(tmpbuf, "0");
 332         }
 333         printf("BFS-fs: %s: lasti=%08lx <%s>\n",
 334                                 prefix, BFS_SB(s)->si_lasti, tmpbuf);
 335         free_page((unsigned long)tmpbuf);
 336 #endif
 337 }
 338
 339 static int bfs_fill_super(struct super_block *s, void *data, int silent)
 340 {
 341         struct buffer_head *bh;
 342         struct bfs_super_block *bfs_sb;
 343         struct inode *inode;
 344         unsigned i, imap_len;
 345         struct bfs_sb_info *info;
 346         long ret = -EINVAL;
 347         unsigned long i_sblock, i_eblock, i_eoff, s_size;
 348
 349         info = kzalloc(sizeof(*info), GFP_KERNEL);
 350         if (!info)
 351                 return -ENOMEM;
 352         s->s_fs_info = info;
 353
 354         sb_set_blocksize(s, BFS_BSIZE);
 355
 356         bh = sb_bread(s, 0);
 357         if(!bh)
 358                 goto out;
 359         bfs_sb = (struct bfs_super_block *)bh->b_data;
 360         if (le32_to_cpu(bfs_sb->s_magic) != BFS_MAGIC) {
 361                 if (!silent)
 362                         printf("No BFS filesystem on %s (magic=%08x)\n",
 363                                 s->s_id,  le32_to_cpu(bfs_sb->s_magic));
 364                 goto out;
 365         }
 366         if (BFS_UNCLEAN(bfs_sb, s) && !silent)
 367                 printf("%s is unclean, continuing\n", s->s_id);
 368
 369         s->s_magic = BFS_MAGIC;
 370         info->si_sbh = bh;
 371
 372         if (le32_to_cpu(bfs_sb->s_start) > le32_to_cpu(bfs_sb->s_end)) {
 373                 printf("Superblock is corrupted\n");
 374                 goto out;
 375         }
 376
 377         info->si_lasti = (le32_to_cpu(bfs_sb->s_start) - BFS_BSIZE) /
 378                                         sizeof(struct bfs_inode)
 379                                         + BFS_ROOT_INO - 1;
 380         imap_len = (info->si_lasti / 8) + 1;
 381         info->si_imap = kzalloc(imap_len, GFP_KERNEL);
 382         if (!info->si_imap)
 383                 goto out;
 384         for (i = 0; i < BFS_ROOT_INO; i++)
 385                 set_bit(i, info->si_imap);
 386
 387         s->s_op = &bfs_sops;
 388         inode = bfs_iget(s, BFS_ROOT_INO);
 389         if (IS_ERR(inode)) {
 390                 ret = PTR_ERR(inode);
 391                 kfree(info->si_imap);
 392                 goto out;
 393         }
 394         s->s_root = d_alloc_root(inode);
 395         if (!s->s_root) {
 396                 iput(inode);
 397                 ret = -ENOMEM;
 398                 kfree(info->si_imap);
 399                 goto out;
 400         }
 401
 402         info->si_blocks = (le32_to_cpu(bfs_sb->s_end) + 1) >> BFS_BSIZE_BITS;
 403         info->si_freeb = (le32_to_cpu(bfs_sb->s_end) + 1
 404                         - le32_to_cpu(bfs_sb->s_start)) >> BFS_BSIZE_BITS;
 405         info->si_freei = 0;
 406         info->si_lf_eblk = 0;
 407
 408         /* can we read the last block? */
 409         bh = sb_bread(s, info->si_blocks - 1);
 410         if (!bh) {
 411                 printf("Last block not available: %lu\n", info->si_blocks - 1);
 412                 iput(inode);
 413                 ret = -EIO;
 414                 kfree(info->si_imap);
 415                 goto out;
 416         }
 417         brelse(bh);
 418
 419         bh = NULL;
 420         for (i = BFS_ROOT_INO; i <= info->si_lasti; i++) {
 421                 struct bfs_inode *di;
 422                 int block = (i - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1;
 423                 int off = (i - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;
 424                 unsigned long eblock;
 425
 426                 if (!off) {
 427                         brelse(bh);
 428                         bh = sb_bread(s, block);
 429                 }
 430
 431                 if (!bh)
 432                         continue;
 433
 434                 di = (struct bfs_inode *)bh->b_data + off;
 435
 436                 /* test if filesystem is not corrupted */
 437
 438                 i_eoff = le32_to_cpu(di->i_eoffset);
 439                 i_sblock = le32_to_cpu(di->i_sblock);
 440                 i_eblock = le32_to_cpu(di->i_eblock);
 441                 s_size = le32_to_cpu(bfs_sb->s_end);
 442
 443                 if (i_sblock > info->si_blocks ||
 444                         i_eblock > info->si_blocks ||
 445                         i_sblock > i_eblock ||
 446                         i_eoff > s_size ||
 447                         i_sblock * BFS_BSIZE > i_eoff) {
 448
 449                         printf("Inode 0x%08x corrupted\n", i);
 450
 451                         brelse(bh);
 452                         s->s_root = NULL;
 453                         kfree(info->si_imap);
 454                         kfree(info);
 455                         s->s_fs_info = NULL;
 456                         return -EIO;
 457                 }
 458
 459                 if (!di->i_ino) {
 460                         info->si_freei++;
 461                         continue;
 462                 }
 463                 set_bit(i, info->si_imap);
 464                 info->si_freeb -= BFS_FILEBLOCKS(di);
 465
 466                 eblock =  le32_to_cpu(di->i_eblock);
 467                 if (eblock > info->si_lf_eblk)
 468                         info->si_lf_eblk = eblock;
 469         }
 470         brelse(bh);
 471         if (!(s->s_flags & MS_RDONLY)) {
 472                 mark_buffer_dirty(info->si_sbh);
 473                 s->s_dirt = 1;
 474         }
 475         dump_imap("read_super", s);
 476         mutex_init(&info->bfs_lock);
 477         return 0;
 478
 479 out:
 480         brelse(bh);
 481         kfree(info);
 482         s->s_fs_info = NULL;
 483         return ret;
 484 }
 485
 486 static int bfs_get_sb(struct file_system_type *fs_type,
 487         int flags, const char *dev_name, void *data, struct vfsmount *mnt)
 488 {
 489         return get_sb_bdev(fs_type, flags, dev_name, data, bfs_fill_super, mnt);
 490 }
 491
 492 static struct file_system_type bfs_fs_type = {
 493         .owner          = THIS_MODULE,
 494         .name           = "bfs",
 495         .get_sb         = bfs_get_sb,
 496         .kill_sb        = kill_block_super,
 497         .fs_flags       = FS_REQUIRES_DEV,
 498 };
 499
 500 static int __init init_bfs_fs(void)
 501 {
 502         int err = init_inodecache();
 503         if (err)
 504                 goto out1;
 505         err = register_filesystem(&bfs_fs_type);
 506         if (err)
 507                 goto out;
 508         return 0;
 509 out:
 510         destroy_inodecache();
 511 out1:
 512         return err;
 513 }
 514
 515 static void __exit exit_bfs_fs(void)
 516 {
 517         unregister_filesystem(&bfs_fs_type);
 518         destroy_inodecache();
 519 }
 520
 521 module_init(init_bfs_fs)
 522 module_exit(exit_bfs_fs)