fs/bfs/inode.c

   1 /*
   2  *      fs/bfs/inode.c
   3  *      BFS superblock and inode operations.
   4  *      Copyright (C) 1999-2006 Tigran Aivazian <[email protected]>
   5  *      From fs/minix, Copyright (C) 1991, 1992 Linus Torvalds.
   6  *
   7  *      Made endianness-clean by Andrew Stribblehill <[email protected]>, 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 <linux/writeback.h>
  19 #include <asm/uaccess.h>
  20 #include "bfs.h"
  21
  22 MODULE_AUTHOR("Tigran Aivazian <[email protected]>");
  23 MODULE_DESCRIPTION("SCO UnixWare BFS filesystem for Linux");
  24 MODULE_LICENSE("GPL");
  25
  26 #undef DEBUG
  27
  28 #ifdef DEBUG
  29 #define dprintf(x...)   printf(x)
  30 #else
  31 #define dprintf(x...)
  32 #endif
  33
  34 static void bfs_write_super(struct super_block *s);
  35 void dump_imap(const char *prefix, struct super_block *s);
  36
  37 struct inode *bfs_iget(struct super_block *sb, unsigned long ino)
  38 {
  39         struct bfs_inode *di;
  40         struct inode *inode;
  41         struct buffer_head *bh;
  42         int block, off;
  43
  44         inode = iget_locked(sb, ino);
  45         if (IS_ERR(inode))
  46                 return ERR_PTR(-ENOMEM);
  47         if (!(inode->i_state & I_NEW))
  48                 return inode;
  49
  50         if ((ino < BFS_ROOT_INO) || (ino > BFS_SB(inode->i_sb)->si_lasti)) {
  51                 printf("Bad inode number %s:%08lx\n", inode->i_sb->s_id, ino);
  52                 goto error;
  53         }
  54
  55         block = (ino - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1;
  56         bh = sb_bread(inode->i_sb, block);
  57         if (!bh) {
  58                 printf("Unable to read inode %s:%08lx\n", inode->i_sb->s_id,
  59                                                                         ino);
  60                 goto error;
  61         }
  62
  63         off = (ino - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;
  64         di = (struct bfs_inode *)bh->b_data + off;
  65
  66         inode->i_mode = 0x0000FFFF & le32_to_cpu(di->i_mode);
  67         if (le32_to_cpu(di->i_vtype) == BFS_VDIR) {
  68                 inode->i_mode |= S_IFDIR;
  69                 inode->i_op = &bfs_dir_inops;
  70                 inode->i_fop = &bfs_dir_operations;
  71         } else if (le32_to_cpu(di->i_vtype) == BFS_VREG) {
  72                 inode->i_mode |= S_IFREG;
  73                 inode->i_op = &bfs_file_inops;
  74                 inode->i_fop = &bfs_file_operations;
  75                 inode->i_mapping->a_ops = &bfs_aops;
  76         }
  77
  78         BFS_I(inode)->i_sblock =  le32_to_cpu(di->i_sblock);
  79         BFS_I(inode)->i_eblock =  le32_to_cpu(di->i_eblock);
  80         BFS_I(inode)->i_dsk_ino = le16_to_cpu(di->i_ino);
  81         inode->i_uid =  le32_to_cpu(di->i_uid);
  82         inode->i_gid =  le32_to_cpu(di->i_gid);
  83         inode->i_nlink =  le32_to_cpu(di->i_nlink);
  84         inode->i_size = BFS_FILESIZE(di);
  85         inode->i_blocks = BFS_FILEBLOCKS(di);
  86         inode->i_atime.tv_sec =  le32_to_cpu(di->i_atime);
  87         inode->i_mtime.tv_sec =  le32_to_cpu(di->i_mtime);
  88         inode->i_ctime.tv_sec =  le32_to_cpu(di->i_ctime);
  89         inode->i_atime.tv_nsec = 0;
  90         inode->i_mtime.tv_nsec = 0;
  91         inode->i_ctime.tv_nsec = 0;
  92
  93         brelse(bh);
  94         unlock_new_inode(inode);
  95         return inode;
  96
  97 error:
  98         iget_failed(inode);
  99         return ERR_PTR(-EIO);
 100 }
 101
 102 static int bfs_write_inode(struct inode *inode, struct writeback_control *wbc)
 103 {
 104         struct bfs_sb_info *info = BFS_SB(inode->i_sb);
 105         unsigned int ino = (u16)inode->i_ino;
 106         unsigned long i_sblock;
 107         struct bfs_inode *di;
 108         struct buffer_head *bh;
 109         int block, off;
 110         int err = 0;
 111
 112         dprintf("ino=%08x\n", ino);
 113
 114         if ((ino < BFS_ROOT_INO) || (ino > BFS_SB(inode->i_sb)->si_lasti)) {
 115                 printf("Bad inode number %s:%08x\n", inode->i_sb->s_id, ino);
 116                 return -EIO;
 117         }
 118
 119         mutex_lock(&info->bfs_lock);
 120         block = (ino - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1;
 121         bh = sb_bread(inode->i_sb, block);
 122         if (!bh) {
 123                 printf("Unable to read inode %s:%08x\n",
 124                                 inode->i_sb->s_id, ino);
 125                 mutex_unlock(&info->bfs_lock);
 126                 return -EIO;
 127         }
 128
 129         off = (ino - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;
 130         di = (struct bfs_inode *)bh->b_data + off;
 131
 132         if (ino == BFS_ROOT_INO)
 133                 di->i_vtype = cpu_to_le32(BFS_VDIR);
 134         else
 135                 di->i_vtype = cpu_to_le32(BFS_VREG);
 136
 137         di->i_ino = cpu_to_le16(ino);
 138         di->i_mode = cpu_to_le32(inode->i_mode);
 139         di->i_uid = cpu_to_le32(inode->i_uid);
 140         di->i_gid = cpu_to_le32(inode->i_gid);
 141         di->i_nlink = cpu_to_le32(inode->i_nlink);
 142         di->i_atime = cpu_to_le32(inode->i_atime.tv_sec);
 143         di->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec);
 144         di->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec);
 145         i_sblock = BFS_I(inode)->i_sblock;
 146         di->i_sblock = cpu_to_le32(i_sblock);
 147         di->i_eblock = cpu_to_le32(BFS_I(inode)->i_eblock);
 148         di->i_eoffset = cpu_to_le32(i_sblock * BFS_BSIZE + inode->i_size - 1);
 149
 150         mark_buffer_dirty(bh);
 151         if (wbc->sync_mode == WB_SYNC_ALL) {
 152                 sync_dirty_buffer(bh);
 153                 if (buffer_req(bh) && !buffer_uptodate(bh))
 154                         err = -EIO;
 155         }
 156         brelse(bh);
 157         mutex_unlock(&info->bfs_lock);
 158         return err;
 159 }
 160
 161 static void bfs_delete_inode(struct inode *inode)
 162 {
 163         unsigned long ino = inode->i_ino;
 164         struct bfs_inode *di;
 165         struct buffer_head *bh;
 166         int block, off;
 167         struct super_block *s = inode->i_sb;
 168         struct bfs_sb_info *info = BFS_SB(s);
 169         struct bfs_inode_info *bi = BFS_I(inode);
 170
 171         dprintf("ino=%08lx\n", ino);
 172
 173         truncate_inode_pages(&inode->i_data, 0);
 174
 175         if ((ino < BFS_ROOT_INO) || (ino > info->si_lasti)) {
 176                 printf("invalid ino=%08lx\n", ino);
 177                 return;
 178         }
 179
 180         inode->i_size = 0;
 181         inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC;
 182         mutex_lock(&info->bfs_lock);
 183         mark_inode_dirty(inode);
 184
 185         block = (ino - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1;
 186         bh = sb_bread(s, block);
 187         if (!bh) {
 188                 printf("Unable to read inode %s:%08lx\n",
 189                                         inode->i_sb->s_id, ino);
 190                 mutex_unlock(&info->bfs_lock);
 191                 return;
 192         }
 193         off = (ino - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;
 194         di = (struct bfs_inode *)bh->b_data + off;
 195         memset((void *)di, 0, sizeof(struct bfs_inode));
 196         mark_buffer_dirty(bh);
 197         brelse(bh);
 198
 199         if (bi->i_dsk_ino) {
 200                 if (bi->i_sblock)
 201                         info->si_freeb += bi->i_eblock + 1 - bi->i_sblock;
 202                 info->si_freei++;
 203                 clear_bit(ino, info->si_imap);
 204                 dump_imap("delete_inode", s);
 205         }
 206
 207         /*
 208          * If this was the last file, make the previous block
 209          * "last block of the last file" even if there is no
 210          * real file there, saves us 1 gap.
 211          */
 212         if (info->si_lf_eblk == bi->i_eblock) {
 213                 info->si_lf_eblk = bi->i_sblock - 1;
 214                 mark_buffer_dirty(info->si_sbh);
 215         }
 216         mutex_unlock(&info->bfs_lock);
 217         clear_inode(inode);
 218 }
 219
 220 static int bfs_sync_fs(struct super_block *sb, int wait)
 221 {
 222         struct bfs_sb_info *info = BFS_SB(sb);
 223
 224         mutex_lock(&info->bfs_lock);
 225         mark_buffer_dirty(info->si_sbh);
 226         sb->s_dirt = 0;
 227         mutex_unlock(&info->bfs_lock);
 228
 229         return 0;
 230 }
 231
 232 static void bfs_write_super(struct super_block *sb)
 233 {
 234         if (!(sb->s_flags & MS_RDONLY))
 235                 bfs_sync_fs(sb, 1);
 236         else
 237                 sb->s_dirt = 0;
 238 }
 239
 240 static void bfs_put_super(struct super_block *s)
 241 {
 242         struct bfs_sb_info *info = BFS_SB(s);
 243
 244         if (!info)
 245                 return;
 246
 247         lock_kernel();
 248
 249         if (s->s_dirt)
 250                 bfs_write_super(s);
 251
 252         brelse(info->si_sbh);
 253         mutex_destroy(&info->bfs_lock);
 254         kfree(info->si_imap);
 255         kfree(info);
 256         s->s_fs_info = NULL;
 257
 258         unlock_kernel();
 259 }
 260
 261 static int bfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 262 {
 263         struct super_block *s = dentry->d_sb;
 264         struct bfs_sb_info *info = BFS_SB(s);
 265         u64 id = huge_encode_dev(s->s_bdev->bd_dev);
 266         buf->f_type = BFS_MAGIC;
 267         buf->f_bsize = s->s_blocksize;
 268         buf->f_blocks = info->si_blocks;
 269         buf->f_bfree = buf->f_bavail = info->si_freeb;
 270         buf->f_files = info->si_lasti + 1 - BFS_ROOT_INO;
 271         buf->f_ffree = info->si_freei;
 272         buf->f_fsid.val[0] = (u32)id;
 273         buf->f_fsid.val[1] = (u32)(id >> 32);
 274         buf->f_namelen = BFS_NAMELEN;
 275         return 0;
 276 }
 277
 278 static struct kmem_cache *bfs_inode_cachep;
 279
 280 static struct inode *bfs_alloc_inode(struct super_block *sb)
 281 {
 282         struct bfs_inode_info *bi;
 283         bi = kmem_cache_alloc(bfs_inode_cachep, GFP_KERNEL);
 284         if (!bi)
 285                 return NULL;
 286         return &bi->vfs_inode;
 287 }
 288
 289 static void bfs_destroy_inode(struct inode *inode)
 290 {
 291         kmem_cache_free(bfs_inode_cachep, BFS_I(inode));
 292 }
 293
 294 static void init_once(void *foo)
 295 {
 296         struct bfs_inode_info *bi = foo;
 297
 298         inode_init_once(&bi->vfs_inode);
 299 }
 300
 301 static int init_inodecache(void)
 302 {
 303         bfs_inode_cachep = kmem_cache_create("bfs_inode_cache",
 304                                              sizeof(struct bfs_inode_info),
 305                                              0, (SLAB_RECLAIM_ACCOUNT|
 306                                                 SLAB_MEM_SPREAD),
 307                                              init_once);
 308         if (bfs_inode_cachep == NULL)
 309                 return -ENOMEM;
 310         return 0;
 311 }
 312
 313 static void destroy_inodecache(void)
 314 {
 315         kmem_cache_destroy(bfs_inode_cachep);
 316 }
 317
 318 static const struct super_operations bfs_sops = {
 319         .alloc_inode    = bfs_alloc_inode,
 320         .destroy_inode  = bfs_destroy_inode,
 321         .write_inode    = bfs_write_inode,
 322         .delete_inode   = bfs_delete_inode,
 323         .put_super      = bfs_put_super,
 324         .write_super    = bfs_write_super,
 325         .sync_fs        = bfs_sync_fs,
 326         .statfs         = bfs_statfs,
 327 };
 328
 329 void dump_imap(const char *prefix, struct super_block *s)
 330 {
 331 #ifdef DEBUG
 332         int i;
 333         char *tmpbuf = (char *)get_zeroed_page(GFP_KERNEL);
 334
 335         if (!tmpbuf)
 336                 return;
 337         for (i = BFS_SB(s)->si_lasti; i >= 0; i--) {
 338                 if (i > PAGE_SIZE - 100) break;
 339                 if (test_bit(i, BFS_SB(s)->si_imap))
 340                         strcat(tmpbuf, "1");
 341                 else
 342                         strcat(tmpbuf, "0");
 343         }
 344         printf("BFS-fs: %s: lasti=%08lx <%s>\n",
 345                                 prefix, BFS_SB(s)->si_lasti, tmpbuf);
 346         free_page((unsigned long)tmpbuf);
 347 #endif
 348 }
 349
 350 static int bfs_fill_super(struct super_block *s, void *data, int silent)
 351 {
 352         struct buffer_head *bh;
 353         struct bfs_super_block *bfs_sb;
 354         struct inode *inode;
 355         unsigned i, imap_len;
 356         struct bfs_sb_info *info;
 357         int ret = -EINVAL;
 358         unsigned long i_sblock, i_eblock, i_eoff, s_size;
 359
 360         info = kzalloc(sizeof(*info), GFP_KERNEL);
 361         if (!info)
 362                 return -ENOMEM;
 363         mutex_init(&info->bfs_lock);
 364         s->s_fs_info = info;
 365
 366         sb_set_blocksize(s, BFS_BSIZE);
 367
 368         info->si_sbh = sb_bread(s, 0);
 369         if (!info->si_sbh)
 370                 goto out;
 371         bfs_sb = (struct bfs_super_block *)info->si_sbh->b_data;
 372         if (le32_to_cpu(bfs_sb->s_magic) != BFS_MAGIC) {
 373                 if (!silent)
 374                         printf("No BFS filesystem on %s (magic=%08x)\n",
 375                                 s->s_id,  le32_to_cpu(bfs_sb->s_magic));
 376                 goto out1;
 377         }
 378         if (BFS_UNCLEAN(bfs_sb, s) && !silent)
 379                 printf("%s is unclean, continuing\n", s->s_id);
 380
 381         s->s_magic = BFS_MAGIC;
 382
 383         if (le32_to_cpu(bfs_sb->s_start) > le32_to_cpu(bfs_sb->s_end)) {
 384                 printf("Superblock is corrupted\n");
 385                 goto out1;
 386         }
 387
 388         info->si_lasti = (le32_to_cpu(bfs_sb->s_start) - BFS_BSIZE) /
 389                                         sizeof(struct bfs_inode)
 390                                         + BFS_ROOT_INO - 1;
 391         imap_len = (info->si_lasti / 8) + 1;
 392         info->si_imap = kzalloc(imap_len, GFP_KERNEL);
 393         if (!info->si_imap)
 394                 goto out1;
 395         for (i = 0; i < BFS_ROOT_INO; i++)
 396                 set_bit(i, info->si_imap);
 397
 398         s->s_op = &bfs_sops;
 399         inode = bfs_iget(s, BFS_ROOT_INO);
 400         if (IS_ERR(inode)) {
 401                 ret = PTR_ERR(inode);
 402                 goto out2;
 403         }
 404         s->s_root = d_alloc_root(inode);
 405         if (!s->s_root) {
 406                 iput(inode);
 407                 ret = -ENOMEM;
 408                 goto out2;
 409         }
 410
 411         info->si_blocks = (le32_to_cpu(bfs_sb->s_end) + 1) >> BFS_BSIZE_BITS;
 412         info->si_freeb = (le32_to_cpu(bfs_sb->s_end) + 1
 413                         - le32_to_cpu(bfs_sb->s_start)) >> BFS_BSIZE_BITS;
 414         info->si_freei = 0;
 415         info->si_lf_eblk = 0;
 416
 417         /* can we read the last block? */
 418         bh = sb_bread(s, info->si_blocks - 1);
 419         if (!bh) {
 420                 printf("Last block not available: %lu\n", info->si_blocks - 1);
 421                 ret = -EIO;
 422                 goto out3;
 423         }
 424         brelse(bh);
 425
 426         bh = NULL;
 427         for (i = BFS_ROOT_INO; i <= info->si_lasti; i++) {
 428                 struct bfs_inode *di;
 429                 int block = (i - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1;
 430                 int off = (i - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;
 431                 unsigned long eblock;
 432
 433                 if (!off) {
 434                         brelse(bh);
 435                         bh = sb_bread(s, block);
 436                 }
 437
 438                 if (!bh)
 439                         continue;
 440
 441                 di = (struct bfs_inode *)bh->b_data + off;
 442
 443                 /* test if filesystem is not corrupted */
 444
 445                 i_eoff = le32_to_cpu(di->i_eoffset);
 446                 i_sblock = le32_to_cpu(di->i_sblock);
 447                 i_eblock = le32_to_cpu(di->i_eblock);
 448                 s_size = le32_to_cpu(bfs_sb->s_end);
 449
 450                 if (i_sblock > info->si_blocks ||
 451                         i_eblock > info->si_blocks ||
 452                         i_sblock > i_eblock ||
 453                         i_eoff > s_size ||
 454                         i_sblock * BFS_BSIZE > i_eoff) {
 455
 456                         printf("Inode 0x%08x corrupted\n", i);
 457
 458                         brelse(bh);
 459                         ret = -EIO;
 460                         goto out3;
 461                 }
 462
 463                 if (!di->i_ino) {
 464                         info->si_freei++;
 465                         continue;
 466                 }
 467                 set_bit(i, info->si_imap);
 468                 info->si_freeb -= BFS_FILEBLOCKS(di);
 469
 470                 eblock =  le32_to_cpu(di->i_eblock);
 471                 if (eblock > info->si_lf_eblk)
 472                         info->si_lf_eblk = eblock;
 473         }
 474         brelse(bh);
 475         if (!(s->s_flags & MS_RDONLY)) {
 476                 mark_buffer_dirty(info->si_sbh);
 477                 s->s_dirt = 1;
 478         }
 479         dump_imap("read_super", s);
 480         return 0;
 481
 482 out3:
 483         dput(s->s_root);
 484         s->s_root = NULL;
 485 out2:
 486         kfree(info->si_imap);
 487 out1:
 488         brelse(info->si_sbh);
 489 out:
 490         mutex_destroy(&info->bfs_lock);
 491         kfree(info);
 492         s->s_fs_info = NULL;
 493         return ret;
 494 }
 495
 496 static int bfs_get_sb(struct file_system_type *fs_type,
 497         int flags, const char *dev_name, void *data, struct vfsmount *mnt)
 498 {
 499         return get_sb_bdev(fs_type, flags, dev_name, data, bfs_fill_super, mnt);
 500 }
 501
 502 static struct file_system_type bfs_fs_type = {
 503         .owner          = THIS_MODULE,
 504         .name           = "bfs",
 505         .get_sb         = bfs_get_sb,
 506         .kill_sb        = kill_block_super,
 507         .fs_flags       = FS_REQUIRES_DEV,
 508 };
 509
 510 static int __init init_bfs_fs(void)
 511 {
 512         int err = init_inodecache();
 513         if (err)
 514                 goto out1;
 515         err = register_filesystem(&bfs_fs_type);
 516         if (err)
 517                 goto out;
 518         return 0;
 519 out:
 520         destroy_inodecache();
 521 out1:
 522         return err;
 523 }
 524
 525 static void __exit exit_bfs_fs(void)
 526 {
 527         unregister_filesystem(&bfs_fs_type);
 528         destroy_inodecache();
 529 }
 530
 531 module_init(init_bfs_fs)
 532 module_exit(exit_bfs_fs)