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/buffer_head.h>
  16 #include <linux/vfs.h>
  17 #include <linux/writeback.h>
  18 #include <linux/uio.h>
  19 #include <asm/uaccess.h>
  20 #include "bfs.h"
  21
  22 MODULE_AUTHOR("Tigran Aivazian <tigran@aivazian.fsnet.co.uk>");
  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 struct inode *bfs_iget(struct super_block *sb, unsigned long ino)
  35 {
  36         struct bfs_inode *di;
  37         struct inode *inode;
  38         struct buffer_head *bh;
  39         int block, off;
  40
  41         inode = iget_locked(sb, ino);
  42         if (!inode)
  43                 return ERR_PTR(-ENOMEM);
  44         if (!(inode->i_state & I_NEW))
  45                 return inode;
  46
  47         if ((ino < BFS_ROOT_INO) || (ino > BFS_SB(inode->i_sb)->si_lasti)) {
  48                 printf("Bad inode number %s:%08lx\n", inode->i_sb->s_id, ino);
  49                 goto error;
  50         }
  51
  52         block = (ino - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1;
  53         bh = sb_bread(inode->i_sb, block);
  54         if (!bh) {
  55                 printf("Unable to read inode %s:%08lx\n", inode->i_sb->s_id,
  56                                                                         ino);
  57                 goto error;
  58         }
  59
  60         off = (ino - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;
  61         di = (struct bfs_inode *)bh->b_data + off;
  62
  63         inode->i_mode = 0x0000FFFF & le32_to_cpu(di->i_mode);
  64         if (le32_to_cpu(di->i_vtype) == BFS_VDIR) {
  65                 inode->i_mode |= S_IFDIR;
  66                 inode->i_op = &bfs_dir_inops;
  67                 inode->i_fop = &bfs_dir_operations;
  68         } else if (le32_to_cpu(di->i_vtype) == BFS_VREG) {
  69                 inode->i_mode |= S_IFREG;
  70                 inode->i_op = &bfs_file_inops;
  71                 inode->i_fop = &bfs_file_operations;
  72                 inode->i_mapping->a_ops = &bfs_aops;
  73         }
  74
  75         BFS_I(inode)->i_sblock =  le32_to_cpu(di->i_sblock);
  76         BFS_I(inode)->i_eblock =  le32_to_cpu(di->i_eblock);
  77         BFS_I(inode)->i_dsk_ino = le16_to_cpu(di->i_ino);
  78         i_uid_write(inode, le32_to_cpu(di->i_uid));
  79         i_gid_write(inode,  le32_to_cpu(di->i_gid));
  80         set_nlink(inode, le32_to_cpu(di->i_nlink));
  81         inode->i_size = BFS_FILESIZE(di);
  82         inode->i_blocks = BFS_FILEBLOCKS(di);
  83         inode->i_atime.tv_sec =  le32_to_cpu(di->i_atime);
  84         inode->i_mtime.tv_sec =  le32_to_cpu(di->i_mtime);
  85         inode->i_ctime.tv_sec =  le32_to_cpu(di->i_ctime);
  86         inode->i_atime.tv_nsec = 0;
  87         inode->i_mtime.tv_nsec = 0;
  88         inode->i_ctime.tv_nsec = 0;
  89
  90         brelse(bh);
  91         unlock_new_inode(inode);
  92         return inode;
  93
  94 error:
  95         iget_failed(inode);
  96         return ERR_PTR(-EIO);
  97 }
  98
  99 static struct bfs_inode *find_inode(struct super_block *sb, u16 ino, struct buffer_head **p)
 100 {
 101         if ((ino < BFS_ROOT_INO) || (ino > BFS_SB(sb)->si_lasti)) {
 102                 printf("Bad inode number %s:%08x\n", sb->s_id, ino);
 103                 return ERR_PTR(-EIO);
 104         }
 105
 106         ino -= BFS_ROOT_INO;
 107
 108         *p = sb_bread(sb, 1 + ino / BFS_INODES_PER_BLOCK);
 109         if (!*p) {
 110                 printf("Unable to read inode %s:%08x\n", sb->s_id, ino);
 111                 return ERR_PTR(-EIO);
 112         }
 113
 114         return (struct bfs_inode *)(*p)->b_data +  ino % BFS_INODES_PER_BLOCK;
 115 }
 116
 117 static int bfs_write_inode(struct inode *inode, struct writeback_control *wbc)
 118 {
 119         struct bfs_sb_info *info = BFS_SB(inode->i_sb);
 120         unsigned int ino = (u16)inode->i_ino;
 121         unsigned long i_sblock;
 122         struct bfs_inode *di;
 123         struct buffer_head *bh;
 124         int err = 0;
 125
 126         dprintf("ino=%08x\n", ino);
 127
 128         di = find_inode(inode->i_sb, ino, &bh);
 129         if (IS_ERR(di))
 130                 return PTR_ERR(di);
 131
 132         mutex_lock(&info->bfs_lock);
 133
 134         if (ino == BFS_ROOT_INO)
 135                 di->i_vtype = cpu_to_le32(BFS_VDIR);
 136         else
 137                 di->i_vtype = cpu_to_le32(BFS_VREG);
 138
 139         di->i_ino = cpu_to_le16(ino);
 140         di->i_mode = cpu_to_le32(inode->i_mode);
 141         di->i_uid = cpu_to_le32(i_uid_read(inode));
 142         di->i_gid = cpu_to_le32(i_gid_read(inode));
 143         di->i_nlink = cpu_to_le32(inode->i_nlink);
 144         di->i_atime = cpu_to_le32(inode->i_atime.tv_sec);
 145         di->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec);
 146         di->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec);
 147         i_sblock = BFS_I(inode)->i_sblock;
 148         di->i_sblock = cpu_to_le32(i_sblock);
 149         di->i_eblock = cpu_to_le32(BFS_I(inode)->i_eblock);
 150         di->i_eoffset = cpu_to_le32(i_sblock * BFS_BSIZE + inode->i_size - 1);
 151
 152         mark_buffer_dirty(bh);
 153         if (wbc->sync_mode == WB_SYNC_ALL) {
 154                 sync_dirty_buffer(bh);
 155                 if (buffer_req(bh) && !buffer_uptodate(bh))
 156                         err = -EIO;
 157         }
 158         brelse(bh);
 159         mutex_unlock(&info->bfs_lock);
 160         return err;
 161 }
 162
 163 static void bfs_evict_inode(struct inode *inode)
 164 {
 165         unsigned long ino = inode->i_ino;
 166         struct bfs_inode *di;
 167         struct buffer_head *bh;
 168         struct super_block *s = inode->i_sb;
 169         struct bfs_sb_info *info = BFS_SB(s);
 170         struct bfs_inode_info *bi = BFS_I(inode);
 171
 172         dprintf("ino=%08lx\n", ino);
 173
 174         truncate_inode_pages_final(&inode->i_data);
 175         invalidate_inode_buffers(inode);
 176         clear_inode(inode);
 177
 178         if (inode->i_nlink)
 179                 return;
 180
 181         di = find_inode(s, inode->i_ino, &bh);
 182         if (IS_ERR(di))
 183                 return;
 184
 185         mutex_lock(&info->bfs_lock);
 186         /* clear on-disk inode */
 187         memset(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                 bfs_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         mutex_unlock(&info->bfs_lock);
 207 }
 208
 209 static void bfs_put_super(struct super_block *s)
 210 {
 211         struct bfs_sb_info *info = BFS_SB(s);
 212
 213         if (!info)
 214                 return;
 215
 216         mutex_destroy(&info->bfs_lock);
 217         kfree(info->si_imap);
 218         kfree(info);
 219         s->s_fs_info = NULL;
 220 }
 221
 222 static int bfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 223 {
 224         struct super_block *s = dentry->d_sb;
 225         struct bfs_sb_info *info = BFS_SB(s);
 226         u64 id = huge_encode_dev(s->s_bdev->bd_dev);
 227         buf->f_type = BFS_MAGIC;
 228         buf->f_bsize = s->s_blocksize;
 229         buf->f_blocks = info->si_blocks;
 230         buf->f_bfree = buf->f_bavail = info->si_freeb;
 231         buf->f_files = info->si_lasti + 1 - BFS_ROOT_INO;
 232         buf->f_ffree = info->si_freei;
 233         buf->f_fsid.val[0] = (u32)id;
 234         buf->f_fsid.val[1] = (u32)(id >> 32);
 235         buf->f_namelen = BFS_NAMELEN;
 236         return 0;
 237 }
 238
 239 static struct kmem_cache *bfs_inode_cachep;
 240
 241 static struct inode *bfs_alloc_inode(struct super_block *sb)
 242 {
 243         struct bfs_inode_info *bi;
 244         bi = kmem_cache_alloc(bfs_inode_cachep, GFP_KERNEL);
 245         if (!bi)
 246                 return NULL;
 247         return &bi->vfs_inode;
 248 }
 249
 250 static void bfs_i_callback(struct rcu_head *head)
 251 {
 252         struct inode *inode = container_of(head, struct inode, i_rcu);
 253         kmem_cache_free(bfs_inode_cachep, BFS_I(inode));
 254 }
 255
 256 static void bfs_destroy_inode(struct inode *inode)
 257 {
 258         call_rcu(&inode->i_rcu, bfs_i_callback);
 259 }
 260
 261 static void init_once(void *foo)
 262 {
 263         struct bfs_inode_info *bi = foo;
 264
 265         inode_init_once(&bi->vfs_inode);
 266 }
 267
 268 static int __init init_inodecache(void)
 269 {
 270         bfs_inode_cachep = kmem_cache_create("bfs_inode_cache",
 271                                              sizeof(struct bfs_inode_info),
 272                                              0, (SLAB_RECLAIM_ACCOUNT|
 273                                                 SLAB_MEM_SPREAD|SLAB_ACCOUNT),
 274                                              init_once);
 275         if (bfs_inode_cachep == NULL)
 276                 return -ENOMEM;
 277         return 0;
 278 }
 279
 280 static void destroy_inodecache(void)
 281 {
 282         /*
 283          * Make sure all delayed rcu free inodes are flushed before we
 284          * destroy cache.
 285          */
 286         rcu_barrier();
 287         kmem_cache_destroy(bfs_inode_cachep);
 288 }
 289
 290 static const struct super_operations bfs_sops = {
 291         .alloc_inode    = bfs_alloc_inode,
 292         .destroy_inode  = bfs_destroy_inode,
 293         .write_inode    = bfs_write_inode,
 294         .evict_inode    = bfs_evict_inode,
 295         .put_super      = bfs_put_super,
 296         .statfs         = bfs_statfs,
 297 };
 298
 299 void bfs_dump_imap(const char *prefix, struct super_block *s)
 300 {
 301 #ifdef DEBUG
 302         int i;
 303         char *tmpbuf = (char *)get_zeroed_page(GFP_KERNEL);
 304
 305         if (!tmpbuf)
 306                 return;
 307         for (i = BFS_SB(s)->si_lasti; i >= 0; i--) {
 308                 if (i > PAGE_SIZE - 100) break;
 309                 if (test_bit(i, BFS_SB(s)->si_imap))
 310                         strcat(tmpbuf, "1");
 311                 else
 312                         strcat(tmpbuf, "0");
 313         }
 314         printf("BFS-fs: %s: lasti=%08lx <%s>\n",
 315                                 prefix, BFS_SB(s)->si_lasti, tmpbuf);
 316         free_page((unsigned long)tmpbuf);
 317 #endif
 318 }
 319
 320 static int bfs_fill_super(struct super_block *s, void *data, int silent)
 321 {
 322         struct buffer_head *bh, *sbh;
 323         struct bfs_super_block *bfs_sb;
 324         struct inode *inode;
 325         unsigned i, imap_len;
 326         struct bfs_sb_info *info;
 327         int ret = -EINVAL;
 328         unsigned long i_sblock, i_eblock, i_eoff, s_size;
 329
 330         info = kzalloc(sizeof(*info), GFP_KERNEL);
 331         if (!info)
 332                 return -ENOMEM;
 333         mutex_init(&info->bfs_lock);
 334         s->s_fs_info = info;
 335
 336         sb_set_blocksize(s, BFS_BSIZE);
 337
 338         sbh = sb_bread(s, 0);
 339         if (!sbh)
 340                 goto out;
 341         bfs_sb = (struct bfs_super_block *)sbh->b_data;
 342         if (le32_to_cpu(bfs_sb->s_magic) != BFS_MAGIC) {
 343                 if (!silent)
 344                         printf("No BFS filesystem on %s (magic=%08x)\n",
 345                                 s->s_id,  le32_to_cpu(bfs_sb->s_magic));
 346                 goto out1;
 347         }
 348         if (BFS_UNCLEAN(bfs_sb, s) && !silent)
 349                 printf("%s is unclean, continuing\n", s->s_id);
 350
 351         s->s_magic = BFS_MAGIC;
 352
 353         if (le32_to_cpu(bfs_sb->s_start) > le32_to_cpu(bfs_sb->s_end) ||
 354             le32_to_cpu(bfs_sb->s_start) < BFS_BSIZE) {
 355                 printf("Superblock is corrupted\n");
 356                 goto out1;
 357         }
 358
 359         info->si_lasti = (le32_to_cpu(bfs_sb->s_start) - BFS_BSIZE) /
 360                                         sizeof(struct bfs_inode)
 361                                         + BFS_ROOT_INO - 1;
 362         imap_len = (info->si_lasti / 8) + 1;
 363         info->si_imap = kzalloc(imap_len, GFP_KERNEL | __GFP_NOWARN);
 364         if (!info->si_imap) {
 365                 printf("Cannot allocate %u bytes\n", imap_len);
 366                 goto out1;
 367         }
 368         for (i = 0; i < BFS_ROOT_INO; i++)
 369                 set_bit(i, info->si_imap);
 370
 371         s->s_op = &bfs_sops;
 372         inode = bfs_iget(s, BFS_ROOT_INO);
 373         if (IS_ERR(inode)) {
 374                 ret = PTR_ERR(inode);
 375                 goto out2;
 376         }
 377         s->s_root = d_make_root(inode);
 378         if (!s->s_root) {
 379                 ret = -ENOMEM;
 380                 goto out2;
 381         }
 382
 383         info->si_blocks = (le32_to_cpu(bfs_sb->s_end) + 1) >> BFS_BSIZE_BITS;
 384         info->si_freeb = (le32_to_cpu(bfs_sb->s_end) + 1
 385                         - le32_to_cpu(bfs_sb->s_start)) >> BFS_BSIZE_BITS;
 386         info->si_freei = 0;
 387         info->si_lf_eblk = 0;
 388
 389         /* can we read the last block? */
 390         bh = sb_bread(s, info->si_blocks - 1);
 391         if (!bh) {
 392                 printf("Last block not available: %lu\n", info->si_blocks - 1);
 393                 ret = -EIO;
 394                 goto out3;
 395         }
 396         brelse(bh);
 397
 398         bh = NULL;
 399         for (i = BFS_ROOT_INO; i <= info->si_lasti; i++) {
 400                 struct bfs_inode *di;
 401                 int block = (i - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1;
 402                 int off = (i - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;
 403                 unsigned long eblock;
 404
 405                 if (!off) {
 406                         brelse(bh);
 407                         bh = sb_bread(s, block);
 408                 }
 409
 410                 if (!bh)
 411                         continue;
 412
 413                 di = (struct bfs_inode *)bh->b_data + off;
 414
 415                 /* test if filesystem is not corrupted */
 416
 417                 i_eoff = le32_to_cpu(di->i_eoffset);
 418                 i_sblock = le32_to_cpu(di->i_sblock);
 419                 i_eblock = le32_to_cpu(di->i_eblock);
 420                 s_size = le32_to_cpu(bfs_sb->s_end);
 421
 422                 if (i_sblock > info->si_blocks ||
 423                         i_eblock > info->si_blocks ||
 424                         i_sblock > i_eblock ||
 425                         i_eoff > s_size ||
 426                         i_sblock * BFS_BSIZE > i_eoff) {
 427
 428                         printf("Inode 0x%08x corrupted\n", i);
 429
 430                         brelse(bh);
 431                         ret = -EIO;
 432                         goto out3;
 433                 }
 434
 435                 if (!di->i_ino) {
 436                         info->si_freei++;
 437                         continue;
 438                 }
 439                 set_bit(i, info->si_imap);
 440                 info->si_freeb -= BFS_FILEBLOCKS(di);
 441
 442                 eblock =  le32_to_cpu(di->i_eblock);
 443                 if (eblock > info->si_lf_eblk)
 444                         info->si_lf_eblk = eblock;
 445         }
 446         brelse(bh);
 447         brelse(sbh);
 448         bfs_dump_imap("read_super", s);
 449         return 0;
 450
 451 out3:
 452         dput(s->s_root);
 453         s->s_root = NULL;
 454 out2:
 455         kfree(info->si_imap);
 456 out1:
 457         brelse(sbh);
 458 out:
 459         mutex_destroy(&info->bfs_lock);
 460         kfree(info);
 461         s->s_fs_info = NULL;
 462         return ret;
 463 }
 464
 465 static struct dentry *bfs_mount(struct file_system_type *fs_type,
 466         int flags, const char *dev_name, void *data)
 467 {
 468         return mount_bdev(fs_type, flags, dev_name, data, bfs_fill_super);
 469 }
 470
 471 static struct file_system_type bfs_fs_type = {
 472         .owner          = THIS_MODULE,
 473         .name           = "bfs",
 474         .mount          = bfs_mount,
 475         .kill_sb        = kill_block_super,
 476         .fs_flags       = FS_REQUIRES_DEV,
 477 };
 478 MODULE_ALIAS_FS("bfs");
 479
 480 static int __init init_bfs_fs(void)
 481 {
 482         int err = init_inodecache();
 483         if (err)
 484                 goto out1;
 485         err = register_filesystem(&bfs_fs_type);
 486         if (err)
 487                 goto out;
 488         return 0;
 489 out:
 490         destroy_inodecache();
 491 out1:
 492         return err;
 493 }
 494
 495 static void __exit exit_bfs_fs(void)
 496 {
 497         unregister_filesystem(&bfs_fs_type);
 498         destroy_inodecache();
 499 }
 500
 501 module_init(init_bfs_fs)
 502 module_exit(exit_bfs_fs)